IBM ^ Certification Study Guide -
pSeries AIX System Administration
December 2001
International Technical Support Organization
SG24-6191-00
© Copyright International Business Machines Corporation 2001. All rights reserved.
Note to U.S Government Users – Documentation related to restricted rights – Use, duplication or disclosure is subject to
restrictions set forth in GSA ADP Schedule Contract with IBM Corp.
First Edition (December 2001)
This edition applies to AIX 5L for POWER Version 5.1, program number 5765-E61 and subsequent
releases running on an RS/6000 or pSeries server and is based on information available in
October 2001.
This document was updated on December 6, 2004.
Comments may be addressed to:
IBM Corporation, International Technical Support Organization
Dept. JN9B Building 003 Internal Zip 2834
11400 Burnet Road
Austin, Texas 78758-3493
When you send information to IBM, you grant IBM a non-exclusive right to use or distribute the
information in any way it believes appropriate without incurring any obligation to you.
Take Note! Before using this information and the product it supports, be sure to read the
general information in “Special notices” on page 457.
© Copyright IBM Corp. 2001 3
Contents
Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
The team that wrote this redbook. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Special notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
IBM trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Comments welcome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Chapter 1. Certification overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 pSeries AIX System Administration (Test 191) . . . . . . . . . . . . . . . . . . . 2
1.1.1 Recommended prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.2 Registration for the certification exam. . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.3 Certification exam objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Certification education courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3 Education on CD-ROM: IBM AIX Essentials . . . . . . . . . . . . . . . . . . . . . 9
Chapter 2. System startup problem handling. . . . . . . . . . . . . . . . . . . . . . . 11
2.1 Key commands used throughout the chapter . . . . . . . . . . . . . . . . . . . 12
2.2 Boot process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.3 Power on sequence, LEDs, and audio signals . . . . . . . . . . . . . . . . . . 14
2.4 Useful commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.4.1 Using the alog command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.4.2 Using the cfgmgr command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.4.3 Using the last command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.4.4 Using the bootlist command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.4.5 Using the uptime command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.4.6 Using the mpcfg command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.4.7 Using the shutdown command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.5 Troubleshooting boot problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.5.1 Accessing a system that will not boot . . . . . . . . . . . . . . . . . . . . . . . . 28
2.5.2 Problems with installation media. . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.5.3 Common boot time LED error codes and recovery actions . . . . . . . 33
2.6 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.6.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2.7 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Chapter 3. Hardware assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4 IBM ^ Certification Study Guide - pSeries AIX System Administration
3.1 Listing hardware devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.1.1 Using the lsdev command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.1.2 Using the lspv command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.2 Configuring system devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3.3 System management services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.4 Hardware device compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.4.1 Device configuration database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.5 Using the lsattr command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.6 Using SMIT with devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.7 The system error log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.7.1 Using the errdemon command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.7.2 Using the errpt command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.7.3 Using the errlogger command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
3.7.4 Other error handling commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.8 Diagnosing hardware problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.9 The system log. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
3.9.1 The syslogd configuration file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
3.9.2 The format of the configuration file . . . . . . . . . . . . . . . . . . . . . . . . . . 64
3.9.3 Using the system log. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
3.10 Setting up an ASCII terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
3.11 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
3.11.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
3.12 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Chapter 4. System and software installation . . . . . . . . . . . . . . . . . . . . . . . 75
4.1 Base Operating System installation . . . . . . . . . . . . . . . . . . . . . . . . . . 76
4.1.1 New and Complete Overwrite installation . . . . . . . . . . . . . . . . . . . . . 78
4.1.2 Migration installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.1.3 Preservation installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.2 Advanced Options installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
4.2.1 Installation Package Set or Desktop . . . . . . . . . . . . . . . . . . . . . . . . . 80
4.2.2 Enable Trusted Computing Base (TCB) . . . . . . . . . . . . . . . . . . . . . . 80
4.2.3 Enable 64-bit Kernel and JFS2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
4.3 Configuration Assistant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
4.4 Understanding maintenance levels. . . . . . . . . . . . . . . . . . . . . . . . . . . 82
4.5 Software packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4.5.1 Filesets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4.5.2 Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.5.3 Licensed Program Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.5.4 Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.5.5 PTFs and APARs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.6 Installing optional software and service updates. . . . . . . . . . . . . . . . . 86
4.6.1 The installp command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Contents 5
4.6.2 Using SMIT for software maintenance . . . . . . . . . . . . . . . . . . . . . . . 90
4.7 Maintaining optional software (applying updates) . . . . . . . . . . . . . . . . 95
4.7.1 Listing the maintenance level of software . . . . . . . . . . . . . . . . . . . . . 96
4.7.2 Downloading fixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
4.7.3 Displaying and updating installed software to the latest level . . . . . 100
4.8 Creating installation images on a hard disk . . . . . . . . . . . . . . . . . . . 106
4.9 Alternate disk installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
4.9.1 Filesets required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
4.9.2 Alternate disk rootvg cloning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
4.9.3 Alternate mksysb install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
4.10 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
4.10.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
4.11 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Chapter 5. Object Data Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
5.1 ODM commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
5.2 Example of an object class for an ODM database . . . . . . . . . . . . . . 119
5.3 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
5.3.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
5.4 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Chapter 6. Storage management, LVM, and file systems . . . . . . . . . . . . 121
6.1 Logical volume storage concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
6.2 Logical Volume Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
6.2.1 LVM configuration data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
6.2.2 Disk quorum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
6.2.3 Disk mirroring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
6.3 Managing physical volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
6.3.1 Configuration of a physical volume . . . . . . . . . . . . . . . . . . . . . . . . . 130
6.3.2 Making an available disk a physical volume . . . . . . . . . . . . . . . . . . 132
6.3.3 Modifying physical volume characteristics . . . . . . . . . . . . . . . . . . . 132
6.3.4 Removing physical volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
6.3.5 Listing information about physical volumes. . . . . . . . . . . . . . . . . . . 134
6.4 Managing volume groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
6.4.1 Listing volume group characteristics . . . . . . . . . . . . . . . . . . . . . . . . 143
6.4.2 Adding a volume group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
6.4.3 Modifying volume group characteristics . . . . . . . . . . . . . . . . . . . . . 146
6.4.4 Importing and exporting a volume group. . . . . . . . . . . . . . . . . . . . . 148
6.4.5 Varying on and varying off a volume group. . . . . . . . . . . . . . . . . . . 151
6.4.6 Monitoring volume groups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
6.4.7 Reorganizing a volume group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
6.4.8 Synchronizing a volume group . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
6.5 Managing logical volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
6 IBM ^ Certification Study Guide - pSeries AIX System Administration
6.5.1 Adding a logical volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
6.5.2 Removing a logical volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
6.5.3 Reducing the size of a logical volume. . . . . . . . . . . . . . . . . . . . . . . 162
6.5.4 Increasing the size of a logical volume . . . . . . . . . . . . . . . . . . . . . . 163
6.5.5 Copying a logical volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
6.5.6 Splitting copies of a logical volume . . . . . . . . . . . . . . . . . . . . . . . . . 166
6.5.7 Listing logical volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
6.5.8 Logical volume size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
6.6 Managing journaled file systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
6.6.1 Characteristics of the journaled file system. . . . . . . . . . . . . . . . . . . 170
6.6.2 Creating a file system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
6.6.3 Mounting a file system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
6.6.4 Removing a file system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
6.6.5 Increasing the size of a file system . . . . . . . . . . . . . . . . . . . . . . . . . 181
6.6.6 Reducing the size of a file system. . . . . . . . . . . . . . . . . . . . . . . . . . 183
6.6.7 Checking file system consistency . . . . . . . . . . . . . . . . . . . . . . . . . . 184
6.6.8 Initializing the JFS log device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
6.6.9 Placement of the JFS log device. . . . . . . . . . . . . . . . . . . . . . . . . . . 187
6.6.10 Large file enabled file systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
6.7 Troubleshooting file system problems . . . . . . . . . . . . . . . . . . . . . . . 188
6.7.1 Recovering from super block errors . . . . . . . . . . . . . . . . . . . . . . . . 188
6.7.2 Cannot unmount file systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
6.8 Summary of LVM commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
6.8.1 PV commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
6.8.2 VG commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
6.8.3 LV commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
6.8.4 File system commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
6.9 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
6.9.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
6.10 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Chapter 7. System paging space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
7.1 Paging space overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
7.1.1 Paging space considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
7.2 Managing paging spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
7.2.1 Displaying paging space characteristics . . . . . . . . . . . . . . . . . . . . . 202
7.2.2 Adding and activating a paging space . . . . . . . . . . . . . . . . . . . . . . 202
7.2.3 Changing attributes of a paging space . . . . . . . . . . . . . . . . . . . . . . 204
7.2.4 Removing a paging space (except hd6) . . . . . . . . . . . . . . . . . . . . . 207
7.2.5 Managing default paging space (hd6). . . . . . . . . . . . . . . . . . . . . . . 208
7.3 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
7.3.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
7.4 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Contents 7
Chapter 8. System backup, restores, and availability . . . . . . . . . . . . . . . 215
8.1 The mksysb command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
8.1.1 The data layout of a mksysb tape . . . . . . . . . . . . . . . . . . . . . . . . . . 220
8.1.2 Excluding file systems from a backup . . . . . . . . . . . . . . . . . . . . . . . 221
8.1.3 How to create a bootable system backup . . . . . . . . . . . . . . . . . . . . 221
8.1.4 Using mksysb to back up a user volume group . . . . . . . . . . . . . . . 226
8.2 Backing up user information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
8.2.1 Backing up a single volume group . . . . . . . . . . . . . . . . . . . . . . . . . 226
8.2.2 How to backup the current directory . . . . . . . . . . . . . . . . . . . . . . . . 227
8.2.3 Incremental backups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
8.3 Restoring information from backup media . . . . . . . . . . . . . . . . . . . . 229
8.3.1 The tctl command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
8.3.2 How to restore a file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
8.3.3 How to restore a directory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
8.3.4 Errors on restore, incorrect block size. . . . . . . . . . . . . . . . . . . . . . . 236
8.3.5 Using the rmfs command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
8.4 Cloning your system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
8.5 Creating a duplicate copy of a diskette . . . . . . . . . . . . . . . . . . . . . . . 238
8.6 Duplicating a magnetic tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
8.7 Special file notes for rmt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
8.8 High Availability Cluster Multi-Processing (HACMP). . . . . . . . . . . . . 240
8.9 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
8.9.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
8.10 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Chapter 9. System Resource Controller administration . . . . . . . . . . . . . 245
9.1 Starting the SRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
9.1.1 The telinit command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
9.2 Restarting the SRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
9.3 The startsrc command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
9.4 The syslogd daemon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
9.4.1 Starting the syslogd daemon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
9.4.2 syslog configuration file. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
9.4.3 Recycling and refreshing the syslogd daemon . . . . . . . . . . . . . . . . 252
9.4.4 Collecting syslog data from multiple systems . . . . . . . . . . . . . . . . . 252
9.5 Refreshing a daemon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
9.6 The cron daemon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
9.6.1 Crontab file record format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
9.6.2 Allowing access to the crontab command. . . . . . . . . . . . . . . . . . . . 255
9.6.3 Housekeeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
9.7 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
9.7.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
9.8 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
8 IBM ^ Certification Study Guide - pSeries AIX System Administration
Chapter 10. Network administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
10.1 Network startup at boot time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
10.2 Stopping and restarting TCP/IP daemons. . . . . . . . . . . . . . . . . . . . 262
10.2.1 Stopping TCP/IP daemons using the /etc/tcp.clean command . . . 262
10.2.2 Restarting TCP/IP daemons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
10.3 System boot without starting rc.tcpip . . . . . . . . . . . . . . . . . . . . . . . 263
10.4 The inetd daemon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
10.4.1 Starting and refreshing inetd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
10.4.2 Subservers controlled by inetd . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
10.4.3 The /etc/services file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
10.4.4 Stopping inetd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
10.5 The portmap daemon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
10.6 Internet addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
10.6.1 IP address format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
10.6.2 Binary to decimal conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
10.6.3 Internet address classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
10.6.4 Special Internet addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
10.6.5 Subnetting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
10.6.6 Subnet masks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
10.7 Host name resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
10.7.1 The /etc/resolv.conf file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
10.7.2 Related problems with /etc/resolv.conf . . . . . . . . . . . . . . . . . . . . . 279
10.7.3 The nslookup command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
10.8 New adapter considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
10.8.1 Configuring a network adapter using SMIT. . . . . . . . . . . . . . . . . . 281
10.8.2 Configuring a network interface using SMIT . . . . . . . . . . . . . . . . . 281
10.9 Enabling IP forwarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
10.10 Adding network routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
10.11 Changing IP addresses using SMIT . . . . . . . . . . . . . . . . . . . . . . . 286
10.12 The ifconfig command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
10.12.1 Identifying network interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
10.12.2 Activating a network interface . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
10.12.3 Deactivating a network interface . . . . . . . . . . . . . . . . . . . . . . . . . 290
10.12.4 Deleting an address from a network interface. . . . . . . . . . . . . . . 290
10.12.5 Detaching a network interface. . . . . . . . . . . . . . . . . . . . . . . . . . . 290
10.12.6 Creating an IP alias for a network interface . . . . . . . . . . . . . . . . 291
10.12.7 Changing the MTU size of a network interface . . . . . . . . . . . . . . 292
10.13 Network security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
10.13.1 Trusted and non-trusted processes . . . . . . . . . . . . . . . . . . . . . . 293
10.13.2 The $HOME/.netrc file. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
10.13.3 The /etc/hosts.equiv and $HOME/.rhosts files . . . . . . . . . . . . . . 295
10.13.4 The securetcpip command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
10.13.5 Anonymous FTP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Contents 9
10.13.6 FTP logging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
10.14 The uname command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
10.15 Basic network problem determination . . . . . . . . . . . . . . . . . . . . . . 299
10.16 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
10.16.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
10.17 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Chapter 11. Network File System administration. . . . . . . . . . . . . . . . . . . 303
11.1 NFS services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
11.2 Planning, installation, and configuration of NFS . . . . . . . . . . . . . . . 305
11.2.1 Exporting NFS directories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
11.2.2 Unexporting an NFS directory. . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
11.2.3 Mounting an NFS directory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
11.3 Administration of NFS servers and clients . . . . . . . . . . . . . . . . . . . 319
11.3.1 Getting the Current Status of the NFS Daemons . . . . . . . . . . . . . 319
11.3.2 Changing an exported file system. . . . . . . . . . . . . . . . . . . . . . . . . 320
11.3.3 Unmounting a mounted file system. . . . . . . . . . . . . . . . . . . . . . . . 321
11.4 NFS files, commands, and daemons reference. . . . . . . . . . . . . . . . 321
11.4.1 List of NFS Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
11.5 NFS problem determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
11.5.1 Identifying NFS problems checklist. . . . . . . . . . . . . . . . . . . . . . . . 323
11.5.2 Checking network connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
11.5.3 NFS error messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
11.6 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
11.6.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
11.7 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Chapter 12. System performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
12.1 System dynamics and workload . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
12.1.1 System dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
12.1.2 Classes of workloads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
12.1.3 General performance and availability guidelines . . . . . . . . . . . . . 335
12.2 Overview of system performance . . . . . . . . . . . . . . . . . . . . . . . . . . 336
12.3 Base Operating System tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
12.3.1 Using the vmstat command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
12.3.2 Using the iostat command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
12.3.3 Using the netstat command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345
12.3.4 Additional performance related commands. . . . . . . . . . . . . . . . . . 348
12.4 Controlling resource usage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
12.4.1 Using the nice and renice commands . . . . . . . . . . . . . . . . . . . . . . 349
12.4.2 Workload Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
12.5 Performance analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
12.5.1 Determining CPU-bound and memory bound systems. . . . . . . . . 350
10 IBM ^ Certification Study Guide - pSeries AIX System Administration
12.5.2 Idle time calculations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
12.5.3 Calculating paging rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
12.6 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
12.6.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
12.7 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Chapter 13. User administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
13.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
13.2 User administration related commands. . . . . . . . . . . . . . . . . . . . . . 359
13.3 User administration related files . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
13.3.1 /etc/security/environ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360
13.3.2 /etc/security/lastlog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360
13.3.3 /etc/security/limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
13.3.4 /etc/security/user . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362
13.3.5 /usr/lib/security/mkuser.default . . . . . . . . . . . . . . . . . . . . . . . . . . . 364
13.3.6 /usr/lib/security/mkuser.sys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364
13.3.7 /etc/passwd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
13.3.8 /etc/security/passwd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
13.3.9 /etc/security/login.cfg. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
13.3.10 /etc/utmp, /var/adm/wtmp, /etc/security/failedlogin . . . . . . . . . . . 368
13.3.11 /etc/motd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368
13.3.12 /etc/environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369
13.3.13 /etc/profile and $HOME/.profile . . . . . . . . . . . . . . . . . . . . . . . . . . 370
13.4 User administration tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
13.4.1 Adding a new user account. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
13.4.2 Creating or changing user password . . . . . . . . . . . . . . . . . . . . . . 372
13.4.3 Changing user attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
13.4.4 Displaying user attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376
13.4.5 Removing a user account . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378
13.4.6 Changing security attributes of user . . . . . . . . . . . . . . . . . . . . . . . 379
13.4.7 Displaying currently logged users . . . . . . . . . . . . . . . . . . . . . . . . . 381
13.4.8 Preventing user logins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382
13.4.9 Changing a user’s login shell . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382
13.4.10 Changing the shell prompt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383
13.4.11 Starting AIX Common Desktop Environment . . . . . . . . . . . . . . . 384
13.5 Common login errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385
13.5.1 AIX Common Desktop Environment and full file systems . . . . . . . 386
13.6 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
13.6.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388
13.7 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388
Chapter 14. Printing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389
14.1 Creating a new print queue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
Contents 11
14.2 The print configuration file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
14.3 Controlling the print queue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
14.3.1 Editing /etc/qconfig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
14.3.2 Modifying /etc/qconfig while jobs are processing . . . . . . . . . . . . . 402
14.4 Stopping the print queue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
14.5 Starting the print queue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404
14.6 Flushing a print job. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404
14.7 How to check the print spooler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
14.8 Setting the time out on a printer . . . . . . . . . . . . . . . . . . . . . . . . . . . 406
14.9 Basic printer diagnostics checklist . . . . . . . . . . . . . . . . . . . . . . . . . 411
14.10 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412
14.10.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
14.11 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Chapter 15. Sendmail and e-mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
15.1 Overview of mail system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416
15.2 Mail daemons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417
15.2.1 Starting the sendmail daemon . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
15.2.2 Stopping the sendmail daemon. . . . . . . . . . . . . . . . . . . . . . . . . . . 418
15.2.3 Refreshing the sendmail daemon . . . . . . . . . . . . . . . . . . . . . . . . . 418
15.2.4 Getting the status of sendmail daemon. . . . . . . . . . . . . . . . . . . . . 418
15.2.5 Autostart of the sendmail daemon (/etc/rc.tcpip). . . . . . . . . . . . . . 419
15.2.6 Specifying time values in sendmail (in rc.tcpip) . . . . . . . . . . . . . . 419
15.2.7 Specifying time values in sendmail (not in rc.tcpip) . . . . . . . . . . . 419
15.3 Mail queue directory: /var/spool/mqueue . . . . . . . . . . . . . . . . . . . . 420
15.3.1 Printing the mail queue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420
15.3.2 Mail queue files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420
15.3.3 Forcing the mail queue to run . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421
15.3.4 Moving the mail queue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421
15.4 Mail logs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
15.4.1 Managing the mail log files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
15.4.2 Logging mailer statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
15.4.3 Displaying mailer information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
15.5 Mail aliasing and forwarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424
15.5.1 Creating or modifying local system aliases . . . . . . . . . . . . . . . . . . 425
15.5.2 Building the alias database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426
15.5.3 Forwarding mail with /etc/aliases . . . . . . . . . . . . . . . . . . . . . . . . . 426
15.5.4 Forwarding mail with $HOME/.forward . . . . . . . . . . . . . . . . . . . . . 427
15.5.5 Forwarding mail to /dev/null . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
15.6 Mail addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
15.6.1 To address mail to users on your local system . . . . . . . . . . . . . . . 428
15.6.2 To address mail to users on your network . . . . . . . . . . . . . . . . . . 429
15.6.3 To address mail to users on a different network . . . . . . . . . . . . . . 429
12 IBM ^ Certification Study Guide - pSeries AIX System Administration
15.6.4 To address mail over a BNU or UUCP link . . . . . . . . . . . . . . . . . . 429
15.7 Storing mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
15.8 Mail administrator’s reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432
15.8.1 List of mail commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432
15.8.2 List of mail files and directories. . . . . . . . . . . . . . . . . . . . . . . . . . . 432
15.9 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434
15.9.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435
15.10 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435
Chapter 16. Online documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437
16.1 Installing the Web browser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439
16.2 Installing the Web server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440
16.3 Installing Documentation Search Service . . . . . . . . . . . . . . . . . . . . 440
16.4 Configuring Documentation Search Service . . . . . . . . . . . . . . . . . . 441
16.5 Installing online manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442
16.6 Invoking Documentation Search Service . . . . . . . . . . . . . . . . . . . . 443
16.7 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446
16.7.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446
16.8 Exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446
Chapter 17. The AIXwindows font server . . . . . . . . . . . . . . . . . . . . . . . . . 447
17.1 XFS server interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448
17.2 XFS keywords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448
17.3 XFS form conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449
17.4 XFS command flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450
17.5 Font server examples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450
17.6 Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451
17.6.1 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451
17.7 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451
Related publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
IBM Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
Other resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
Referenced Web sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454
How to get IBM Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454
IBM Redbooks collections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455
Special notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457
Abbreviations and acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
© Copyright IBM Corp. 2001 13
Figures
2-1 Displaying diagnostic flags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2-2 Welcome to BOS Installation and Maintenance menu. . . . . . . . . . . . . . 29
2-3 Maintenance menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2-4 Warning message window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2-5 Access a Root Volume Group menu . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2-6 Volume Group Information menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3-1 Listing devices from a pre-defined ODM database . . . . . . . . . . . . . . . . 41
3-2 Listing devices in the customized ODM database . . . . . . . . . . . . . . . . . 42
3-3 Listing available devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3-4 Listing supported devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3-5 Listing physical volume characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 44
3-6 Listing physical volume characteristics by physical partitions . . . . . . . . 45
3-7 diag screen showing a problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
3-8 Attaching a serial terminal to an RS/6000 system . . . . . . . . . . . . . . . . . 69
3-9 Terminal connection to direct-attached asynchronous adapter . . . . . . . 69
3-10 Adding a tty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
4-1 Flow chart for AIX 5L Version 5.1 system installation . . . . . . . . . . . . . . 76
4-2 Welcome to Base Operating System menu . . . . . . . . . . . . . . . . . . . . . . 77
4-3 Installation and Settings menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4-4 Advanced Options menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
4-5 Configuration Assistant menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
4-6 Sample oslevel -l output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4-7 Install and Update from LATEST Available Software menu . . . . . . . . . 91
4-8 Install and Update from LATEST Available Software menu - more . . . . 92
4-9 Commit Applied Software Updates (Remove Saved Files) menu . . . . . 93
4-10 Reject Applied Software Updates (Use Previous Version) menu . . . . . 94
4-11 Remove Installed Software menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
4-12 fixdist - Step 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
4-13 fixdist - Step 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
4-14 Show Fix (APAR) Installation Status menu . . . . . . . . . . . . . . . . . . . . . 102
4-15 Update Software by Fix (APAR) menu . . . . . . . . . . . . . . . . . . . . . . . . 103
4-16 Update Installed Software to Latest Level (Update All) menu . . . . . . . 104
4-17 Update Installed Software to Latest Level (Update All) menu - more . 105
4-18 Copy Software to Hard Disk for Future Installation menu . . . . . . . . . . 106
4-19 Alternate Disk Installation menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
4-20 Clone the rootvg to an Alternate Disk menu . . . . . . . . . . . . . . . . . . . . 109
4-21 Install mksysb on an Alternate Disk menu . . . . . . . . . . . . . . . . . . . . . . 111
6-1 Relationship between logical storage components . . . . . . . . . . . . . . . 122
14 IBM ^ Certification Study Guide - pSeries AIX System Administration
6-2 Disk quorum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
6-3 Status and characteristics of hdisk1 by physical partitions . . . . . . . . . 137
6-4 Physical partition allocation by disk region . . . . . . . . . . . . . . . . . . . . . 138
6-5 migratepv does not work across volume groups . . . . . . . . . . . . . . . . . 139
6-6 smitty migratepv command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
6-7 smitty mkvg command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
6-8 smitty varyonvg command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
6-9 smitty varyoffvg command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
6-10 lsvg rootvg command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
6-11 lsvg -l rootvg command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
6-12 lsvg -p vgname command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
6-13 Mapping of LP to PP for mirrored and non-mirrored data . . . . . . . . . . 158
6-14 Selecting the volume group to hold the new logical volume . . . . . . . . 160
6-15 Setting characteristics of the new logical volume . . . . . . . . . . . . . . . . 161
6-16 smitty cplv command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
6-17 Selecting source and destination logical volumes . . . . . . . . . . . . . . . . 165
6-18 Logical volume listing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
6-19 Logical volume attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
6-20 smitty crjfs command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
6-21 Selecting the volume group to hold the new file system . . . . . . . . . . . 172
6-22 Setting characteristics of the new file system . . . . . . . . . . . . . . . . . . . 173
6-23 smitty crjfs results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
6-24 File tree view before mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
6-25 File tree view after mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
6-26 smitty mount command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
6-27 Mount a File System screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
6-28 Selecting the mount point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
6-29 smitty rmjfs command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
6-30 Selecting the file system to remove . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
6-31 smitty chjfs command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
6-32 Setting new characteristics of a file system . . . . . . . . . . . . . . . . . . . . . 183
6-33 lsfs -q command output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
7-1 vmstat command output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
7-2 topas command output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
7-3 smitty mkps command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
7-4 Add Another Paging Space attributes . . . . . . . . . . . . . . . . . . . . . . . . . 203
7-5 smitty chps command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
7-6 Changing attributes of paging space in AIX Version 4.3 . . . . . . . . . . . 205
7-7 smitty swapoff command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
8-1 Layout of a mksysb tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
8-2 System Management menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
8-3 System Storage Management (Physical & Logical Storage) menu . . . 222
8-4 System Backup Manager menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Figures 15
8-5 Back Up the System menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
8-6 COMMAND STATUS screen during operation . . . . . . . . . . . . . . . . . . 225
8-7 COMMAND STATUS screen after operation. . . . . . . . . . . . . . . . . . . . 225
9-1 Restart of the srcmstr daemon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
9-2 Syslogd stanza in ODM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
9-3 Sample syslog configuration file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
9-4 Sample crontab file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
9-5 /usr/lib/spell/compress script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
10-1 Refreshing the inetd daemon using refresh or kill . . . . . . . . . . . . . . . . 265
10-2 Subservers started in inetd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
10-3 Stopping inetd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
10-4 Telnet and FTP when inetd on sv1166f is down . . . . . . . . . . . . . . . . . 267
10-5 IP address format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
10-6 Binary to decimal conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
10-7 IP address classes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
10-8 Subnetting example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
10-9 Default subnet mask for network classes . . . . . . . . . . . . . . . . . . . . . . 275
10-10 Subnetting scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
10-11 Sample /etc/resolv.conf file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
10-12 Change/Show Characteristics of an Ethernet Adapter menu . . . . . . . 281
10-13 Available Network Interfaces submenu . . . . . . . . . . . . . . . . . . . . . . . . 282
10-14 Add a Standard Ethernet Network Interface menu . . . . . . . . . . . . . . . 283
10-15 Change/Show a Standard Ethernet Interface menu . . . . . . . . . . . . . . 284
10-16 Adding a Static Route menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
10-17 Adding a route using the route add command . . . . . . . . . . . . . . . . . . . 286
10-18 Minimum Configuration & Startup menu . . . . . . . . . . . . . . . . . . . . . . . 287
10-19 A sample .netrc file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
10-20 The uname command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
11-1 A typical NFS environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
11-2 Adding a directory to the export list . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
11-3 Content of /etc/exports for CRoom server . . . . . . . . . . . . . . . . . . . . . . 309
11-4 Example NFS stanza in the /etc/filesystems file . . . . . . . . . . . . . . . . . 311
11-5 Add a File System for Mounting screen. . . . . . . . . . . . . . . . . . . . . . . . 314
11-6 Change the Attributes of an Exported Directory . . . . . . . . . . . . . . . . . 320
11-7 Exhibit for NFS Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
12-1 vmstat report of cpu-bound system . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
13-1 /etc/security/lastlog stanzas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
13-2 Contents of /etc/security/limits file . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362
13-3 Contents of /etc/passwd file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
13-4 Contents of /etc/security/passwd file . . . . . . . . . . . . . . . . . . . . . . . . . . 367
13-5 Contents of /etc/security/login.cfg file . . . . . . . . . . . . . . . . . . . . . . . . . 368
13-6 Sample /etc/motd file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369
13-7 Adding a user. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372
16 IBM ^ Certification Study Guide - pSeries AIX System Administration
13-8 Changing a user password . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
13-9 Entering a user password . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
13-10 Changing user characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375
13-11 smitty users command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377
13-12 Listing user characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378
13-13 Removing a user . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
13-14 chsh command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383
14-1 System Management menu screen - Print Spooling option. . . . . . . . . 392
14-2 Print Spooling menu screen - Add a Print Queue option . . . . . . . . . . . 393
14-3 Add a Print Queue menu screen - print queue selection . . . . . . . . . . . 394
14-4 Print Spooling menu screen - Printer Type selection. . . . . . . . . . . . . . 395
14-5 Print Spooling menu - Print Type selection . . . . . . . . . . . . . . . . . . . . . 395
14-6 Print Spooling menu - Printer Interface selection. . . . . . . . . . . . . . . . . 396
14-7 Print Spooling menu - Parent Adapter selection . . . . . . . . . . . . . . . . . 397
14-8 Add a Print Queue menu - printer characteristics . . . . . . . . . . . . . . . . 398
14-9 New print queue Command Status . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
14-10 Print Spooling menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
14-11 Print Spooling - Change/Show Printer Connection Characteristics . . . 408
14-12 Print Spooling menu - Local Printers . . . . . . . . . . . . . . . . . . . . . . . . . . 409
14-13 Change/Show Printer Connection Characteristics screen . . . . . . . . . . 410
14-14 Changing printer connection characteristics results . . . . . . . . . . . . . . 411
15-1 Overview of mail system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416
15-2 Mail management tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417
15-3 /var/spool/mqueue/log file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
15-4 Displaying mailer information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424
15-5 /etc/aliases File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
15-6 Message path for mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431
16-1 Netscape filesets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439
16-2 Domino Go Webserver filesets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440
16-3 Documentation Search Service filesets . . . . . . . . . . . . . . . . . . . . . . . . 441
16-4 Documentation Search Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444
© Copyright IBM Corp. 2001 17
Tables
2-1 Command flags for alog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2-2 Command flags for cfgmgr. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2-3 Command flags for last . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2-4 Command flags for bootlist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2-5 Valid device names for the bootlist command . . . . . . . . . . . . . . . . . . . . 23
2-6 Command flags for mpcfg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2-7 Command flags for shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2-8 Common startup LEDs and recovery actions . . . . . . . . . . . . . . . . . . . . 33
3-1 lsdev command flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3-2 lspv command flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3-3 cfgmgr command flags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3-4 cfgmgr configuration rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3-5 lsattr command flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3-6 errpt command flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3-7 syslogd daemon flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
3-8 Facilities used in the /etc/syslog.conf file . . . . . . . . . . . . . . . . . . . . . . . . 65
3-9 Priority levels for the /etc/syslog.conf file . . . . . . . . . . . . . . . . . . . . . . . . 66
3-10 Destination description for the /etc/syslog.conf file . . . . . . . . . . . . . . . . 67
4-1 Command flags for oslevel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
4-2 Command flags for installp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
4-3 Command flags for lslpp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4-4 Command flags for instfix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
5-1 ODM Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
6-1 VGDA allocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
6-2 reorgvg command flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
6-3 Key flags for the syncvg command . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
6-4 mklv command flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
6-5 rmlv command flags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
6-6 Allowable nbpi values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
6-7 fsck command flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
8-1 List of backup commands and flags. . . . . . . . . . . . . . . . . . . . . . . . . . . 216
8-2 Common tctl subcommands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
8-3 Tape device special file characteristics . . . . . . . . . . . . . . . . . . . . . . . . 240
9-1 Default srcmstr record in the /etc/inittab file. . . . . . . . . . . . . . . . . . . . . 247
9-2 Flags for the startsrc command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
10-1 IP address classes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
10-2 Subnet mask calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
10-3 Class B subnetting reference chart . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
18 IBM ^ Certification Study Guide - pSeries AIX System Administration
10-4 Class C subnetting reference chart . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
10-5 Common parameters for ifconfig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
11-1 Flags for the mknfs command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
12-1 Key flags for the vmstat command. . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
12-2 vmstat output parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
12-3 Key flags for the iostat command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
12-4 iostat output parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
12-5 Key flags for the netstat command . . . . . . . . . . . . . . . . . . . . . . . . . . . 345
14-1 Print commands and their equivalents. . . . . . . . . . . . . . . . . . . . . . . . . 391
14-2 Flags for the enq command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
14-3 Flags for the qchk command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
14-4 Flags for the lpstat command and enq command equivalents. . . . . . . 405
17-1 XFS keywords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448
17-2 Flags for the xfs command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450
© Copyright IBM Corp. 2001 19
Preface
The AIX and IBM pSeries ^ Certifications offered through the
Professional Certification Program from IBM, are designed to validate the skills
required of technical professionals who work in the powerful and often complex
environments of AIX and IBM ^ pSeries. A complete set of professional
certifications are available. They include:
IBM Certified AIX User
IBM Certified Specialist - AIX System Administration
IBM Certified Specialist - AIX System Support
IBM Certified Specialist - Business Intelligence for RS/6000
IBM Certified Specialist - Domino for RS/6000
IBM ^ Certified Specialist - pSeries AIX System Administration
IBM ^ Certified Specialist - pSeries AIX System Support
IBM ^ Certified Specialist - pSeries Solution Sales
IBM Certified Specialist - RS/6000 Solution Sales
IBM Certified Specialist - RS/6000 SP and PSSP V3
RS/6000 SP - Sales Qualification
IBM Certified Specialist - Web Server for RS/6000
IBM ^ Certified Specialist - pSeries HACMP for AIX
IBM Certified Advanced Technical Expert - RS/6000 AIX
Each certification is developed by following a thorough and rigorous process to
ensure the exam is applicable to the job role, and is a meaningful and
appropriate assessment of skill. Subject Matter Experts who successfully
perform the job, participate throughout the entire development process. These
job incumbents bring a wealth of experience into the development process, thus,
making the exams much more meaningful than the typical test, which only
captures classroom knowledge. These experienced Subject Matter Experts
ensure the exams are relevant to the real world and that the test content is both
useful and valid. The result is a certification of value, which appropriately
measures the skills required to perform the job role.
This redbook is designed as a study guide for professionals wishing to prepare
for the certification exam to achieve: IBM ^ Certified Specialist - pSeries
AIX System Administration.
20 IBM ^ Certification Study Guide - pSeries AIX System Administration
The system administration certification validates a broad scope of AIX
administration skills and the ability to perform general AIX software system
maintenance. The certification is applicable to AIX administration professionals
who conduct the AIX problem determination and resolution activities needed to
successfully support customers, or clients, in an AIX environment, to maintain
system reliability.
This redbook helps AIX administrators seeking a comprehensive and
task-oriented guide for developing the knowledge and skills required for the
certification. It is designed to provide a combination of theory and practical
experience needed for a general understanding of the subject matter. It also
provides sample questions that will help in the evaluation of personal progress
and provide familiarity with the types of questions that will be encountered in the
exam.
This redbook does not replace practical experience you should have, but is an
effective tool that, when combined with education activities and experience,
should prove to be a very useful preparation guide for the exam. Due to the
practical nature of the certification content, this publication can also be used as a
desk-side reference. So, whether you are planning to take the pSeries AIX
System Administration certification exam, or if you just want to validate your AIX
system administration skills, this redbook is for you.
For additional information about certification and instructions on How to Register
for an exam, visit our Web site at:
http://www.ibm.com/certify
Preface 21
The team that wrote this redbook
This redbook was produced by a team of specialists from around the world
working at the International Technical Support Organization, Austin Center.
Christian Pruett is an RS/6000 and IBM ^ pSeries IT Specialist at IBM
Global Services in Boulder, Colorado. He has been working for IBM since July
1999. He has a Bachelor’s degree in History from Colorado State University. He
is an IBM ^ Certified Specialist in pSeries AIX System Administration and
pSeries AIX System Support. His areas of expertise include RS/6000 and IBM
^ pSeries systems, RS/6000 and IBM ^ pSeries hardware, and
AIX installation and system recovery. Currently, he is an account lead for the AIX
Standalone Support team at the IGS NA West GeoPlex Center.
Kristian Strickland is a System Support Specialist in Moncton, New Brunswick,
for Co-op Atlantic, a dynamic Atlantic Canadian co-operative wholesaler. He has
been involved professionally in system administration and support since 1995.
He holds a Bachelor of Science degree in Math and Computer Science from St.
Francis Xavier University, and is an IBM ^ Certified Specialist in pSeries
AIX System Administration and pSeries AIX System Support. His areas of
expertise include AIX and Compaq’s OpenVMS operating systems.
Thanks to the following people for their contributions to this project:
International Technical Support Organization, Austin Center
Wade Wallace
IBM Texas and Atlanta
Darin Hartman and Shannan L. DeBrule
IBM Germany
Volker Haug
Special notice
This publication is intended to help IBM business partners, technical
professionals, and customers of IBM prepare for the pSeries AIX System
Administration exam as part of the IBM ^ Certified Specialist program.
The information in this publication is not intended as the specification of any
programming interfaces that are provided by AIX 5L Version 5.1. See the
PUBLICATIONS section of the IBM Programming Announcement for AIX 5L
Version 5.1 for more information about what publications are considered to be
product documentation.
22 IBM ^ Certification Study Guide - pSeries AIX System Administration
IBM trademarks
The following terms are trademarks of the International Business Machines
Corporation in the United States and/or other countries:
Comments welcome
Your comments are important to us!
We want our IBM Redbooks to be as helpful as possible. Send us your
comments about this or other Redbooks in one of the following ways:
Use the online Contact us review redbook form found at:
ibm.com/redbooks
Send your comments in an Internet note to:
redboo[email protected].com
Mail your comments to the address on page ii.
AFP™
AIX 5L™
DFS™
e (logo)®
IBM.COM™
Language Environment®
Perform™
PowerPC Reference Platform®
PTX®
Redbooks Logo
RS/6000®
SP™
AIX®
AIXwindows®
Domino™
HACMP/6000™
IBM ®
Micro Channel®
PowerPC®
pSeries™
Redbooks™
RISC System/6000®
Sequent®
Versatile Storage Server™
© Copyright IBM Corp. 2001 1
Chapter 1. Certification overview
This chapter provides an overview of the skill requirements for obtaining an IBM
^ Certified Specialist - pSeries AIX System Administration certification.
The following chapters are designed to provide a comprehensive review of
specific topics that are essential for obtaining the certification.
1
2 IBM ^ Certification Study Guide - pSeries AIX System Administration
1.1 pSeries AIX System Administration (Test 191)
This certification validates the ability to install, configure, and perform a broad
range of AIX system administrative activities. The certification is applicable to
AIX system administrators who are responsible for supporting end-users and the
day-to-day operation of an pSeries AIX environment.
To attain the IBM ^ Certified Specialist - pSeries AIX System
Administration certification, candidates must pass one test: Test 191: pSeries
AIX System Administration.
1.1.1 Recommended prerequisites
The following are the recommended prerequisites for this certification.
A minimum of six months experience administering in an AIX Version 4 and
Version 5 environments. Note: Exam 191 contains AIX content up to and
including AIX 5L Version 5.1.
One year of AIX or UNIX user experience.
Training in AIX system administration or equivalent experience.
1.1.2 Registration for the certification exam
For information about how to register for the certification exam, visit the following
Web site:
http://www.ibm.com/certify
1.1.3 Certification exam objectives
The following objectives were used as a basis when the certification exam was
developed. Some of these topics have been regrouped to provide better
organization when discussed in this publication.
Installation and configuration
The following are the installation and configuration topics.
Identify customer’s needs (for example, architecture, scalability, physical
requirements, and so on).
Establish strategy for crisis recovery.
Install base operating system.
Perform initial configurations (for example, networks, paging space, date/time,
root password, and so on).
Chapter 1. Certification overview 3
Install LPPs.
Install and configure other software systems (for example, Netscape).
Apply software updates.
Remove software.
Upgrade operating system (for example, preservation and migration
upgrades).
Create and install a mksysb
Upgrade hardware.
Configure printers and queues (for example, add, change, show, or delete
printers and queues).
Configure and manage resources (for example, manage cron, configure
skulkers, configure power management).
Configure devices (for example, cfgmgr, TTY, parallel and manual devices).
Configure subsystems and subservers (for example, start/stop system
resource manager).
Problem determination
The following are the problem determination topics.
Troubleshoot problems with hardware installation (for example, cable
connections).
Troubleshoot problems with software installation (LED hang, system hang).
Troubleshoot problems with software (disk space, prerequisites, lslpp, and so
on).
Troubleshoot hardware (for example, hardware parameters, cfgmgr,
prerequisites, ODM tools).
Evaluate performance and resource problems (for example, check log files,
skulkers, ps -ef).
System and user maintenance
The following are the system and user maintenance topics.
Identify suspect hardware components before hard failure by monitoring error
logs.
Install necessary patches to prevent known problems.
Reboot servers (gracefully).
Add, delete, and modify users.
4 IBM ^ Certification Study Guide - pSeries AIX System Administration
Modify user environment (for example, modify initialization files, edit .profile,
edit dtwmrc, and so on).
Modify system environment.
Work with Volume Groups (add, import, remove, export, modify, list, and so
on).
Work with physical volumes (add, list).
Work with logical volumes (add, remove modify, list, and so on).
Work with file systems (for example, create, remove, modify, list, and so on).
Modify paging space (increase size, add, remove, activate, list, and so on).
Troubleshoot file system problems (for example, mount/unmount problems,
file system full, and so on).
Troubleshoot paging space problems (for example, low paging space
conditions).
Troubleshoot device related problems (for example, file system not available
at IPL, volume group not varying on IPL, SCSI device problems, and so on).
Back up the system.
Back up the applications.
Back up the application data files.
Restore files from tape.
Establish a backup and recovery process based upon customer
requirements.
Recover the system.
Communications
The following are the communications topics.
Install device driver.
Work with TCP/IP daemons (for example, start and stop TCP/IP daemons).
Create interface (set IP address, set subnet mask, configure DNS).
Configure interface (define node, gateway).
Modify interface (change IP parameters).
Configure TCP/IP services.
Work with NFS (for example, start and stop NFS).
Export directory (exportfs).
Mount remote file system.
Chapter 1. Certification overview 5
Troubleshoot hardware communications problems (for example device
unavailable, device not functioning and so on).
Perform TCP/IP troubleshooting (for example, daemons will not start/stop,
cannot create a telnet session on a server, user cannot log on to server, and
so on).
Perform NFS troubleshooting (for example NFS daemon will not start/stop,
host server is not responding, permission denied error messages).
System performance
The following are the system performance topics.
Manage CPU and memory resources (for example, display CPU/memory
usage, start/stop a processor, and so on).
Manage I/O performance resources.
Manage network performance resources (show network, I/O counts,
connections and queues).
Manage workloads (for example, scheduling, setting up job queue, and so
on).
Manage disk/data (partitions, RAID, mirroring, defragmenting file systems,
and so on).
Security
The following is the security topic.
Modify default password attributes for system users (for example, maxage,
maxlength, maxexpire, minrepeat, and so on)
6 IBM ^ Certification Study Guide - pSeries AIX System Administration
1.2 Certification education courses
Courses are offered to help you prepare for the certification tests. These courses
are recommended, but not required, before taking a certification test. The
following tables show the courses that were available at the time of the
publication of this guide. For a current list, visit the following Web site:
http://www.ibm.com/certify
AIX Version 4 System Administration
Course Number Q1214 (USA), AU14 (Worldwide)
Course Duration Five days
Course Abstract Learn the basic system administration skills to support AIX
RS/6000 running the AIX Version 4 operating system. Build
your skills in configuring and monitoring a single CPU
environment. Administrators who manage systems in a
networked environment should attend additional LAN courses.
Course Content •Install the AIX Version 4 operating system, software
bundles, and filesets.
•Perform a system startup and shutdown.
•Understand and use AIX system management tools.
•Configure ASCII terminals and printer devices.
•Manage physical and logical volumes.
•Perform file systems management.
•Create and manage user and group accounts.
•Use backup and restore commands.
•Use administrative subsystems, including cron, to
schedule system tasks and security to implement
customized access of files and directories.
Chapter 1. Certification overview 7
AIX Version 4 Advanced System Administration
Course Number Q1216 (USA), AU16 (Worldwide)
Course Duration Five days
Course Abstract Learn how to identify possible sources of problems on
stand-alone configurations of the RS/6000 and perform
advanced system administration tasks.
Course Content •Identify the different RS/6000 models and architects.
•Explain the ODM purpose for device configuration.
•Interpret system initialization and problems during the
boot process.
•Customize authentication and set up ACLs.
•Identify the TCB components, commands, and their use.
•Obtain a system dump and define saved data.
•Identify the error logging facility components and reports.
•List ways to invoke diagnostic programs.
•Customize a logical volume for optimal performance and
availability.
•Manage a disk and the data under any circumstance.
•Use the standard AIX commands to identify potential I/O,
disk, CPU, or other bottlenecks on the system.
•Customize SMIT menus and define how SMIT interacts
with the ODM.
•Define the virtual printer database and potential
problems.
•List the terminal attributes and create new terminfo
entries.
•Define the NIM installation procedure.
8 IBM ^ Certification Study Guide - pSeries AIX System Administration
AIX Version 4 Configuring TCP/IP and Accessing the Internet
Course Number Q1107 (USA), AU07 or AU05 (Worldwide)
Course Duration Five days
Course Abstract •Learn how to perform TCP/IP network configuration and
administration on AIX Version 4 RS/6000 systems.
•Learn the skills necessary to begin implementing and
using NFS, NIS, DNS, network printing, static and
dynamic routing, SLIP and SLIPLOGIN, Xstations, and
the Internet.
Course Contents •Describe the basic concepts of TCP/IP protocols and
addressing.
•Explain TCP/IP broadcasting and multicasting.
•Configure, implement, and support TCP/IP on an IBM
RS/6000 system.
•Use networking commands for remote logon, remote
execution, and file transfer.
•Configure SLIP and SLIPLOGIN.
•Use SMIT to configure network printing.
•Connect multiple TCP/IP networks using static and
dynamic routing.
•Implement DNS, NFS, and NIS.
•Perform basic troubleshooting of network problems.
•Configure an Xstation in the AIX environment.
•Explain how to access Internet services.
•Understand and support TCP/IP.
•Plan implementation of NFS.
•Support LAN-attached printers.
•Support AIX networking.
•Determine network problems.
•Implement network file systems.
Chapter 1. Certification overview 9
1.3 Education on CD-ROM: IBM AIX Essentials
The new IBM AIX Essentials series offers a dynamic training experience for
those who need convenient and cost-effective AIX education. The series consists
of five new, content rich, computer-based multimedia training courses based on
highly acclaimed, instructor-led AIX classes that have been successfully taught
by IBM Education and Training for years.
To order, and for more information and answers to your questions you can do one
of the following:
In the U.S., use the online form at the following URL:
http://www.ibm.com/services/learning/spotlight/pseries/cdrom.html
Outside the U.S., contact your IBM sales representative, or contact an IBM
Business Partner.
10 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 11
Chapter 2. System startup problem
handling
This chapter discusses the boot process and the common problems that you
might encounter while the system is in the initialization phase. It also covers the
common commands that are used to manipulate the elements associated with
the boot process.
Upon completing this chapter, you should be able to:
Understand the basics of the boot process and be able to perform an orderly
system shutdown.
Determine and control the devices involved in the boot process.
Access the AIX error log.
Troubleshoot boot problems.
Understand and have memorized basic LED error codes.
2
12 IBM ^ Certification Study Guide - pSeries AIX System Administration
2.1 Key commands used throughout the chapter
The following is a list of the important commands that are used throughout this
chapter.
alog Used to maintain and manage log files. Refer to Section 2.4.1,
“Using the alog command” on page 14 for further details.
cfgmgr Configures devices and optionally installs device software into the
system. Refer to Section 2.4.2, “Using the cfgmgr command” on
page 18 for further details.
last Displays all the previous logins and logoffs that still have entries in
/var/adm/wtmp file. Refer to Section 2.4.3, “Using the last
command” on page 20 for further details.
bootlist Displays and alters the list of boot devices available to the system.
Refer to Section 2.4.4, “Using the bootlist command” on page 22
for further details.
uptime Shows how long the system has been up. Refer to Section 2.4.5,
“Using the uptime command” on page 23 for further details.
mpcfg Enables a user with root authority to manage service information.
Refer to Section 2.4.6, “Using the mpcfg command” on page 24 for
further details.
shutdown Used to shut down the system. Refer to Section 2.4.7, “Using the
shutdown command” on page 26 for further details.
2.2 Boot process
During the boot process, the system tests the hardware, loads and runs the
operating system, and configures devices. To boot the operating system, the
following resources are required:
A boot image that can be loaded after the machine is turned on or reset.
Access to the root and /usr file systems.
There are three types of system boots:
Hard Disk Boot
A machine is started for normal operations with the key in the normal position.
On PCI-based systems with no key locking, this is the default startup mode.
Chapter 2. System startup problem handling 13
Diskless Network Boot
A diskless or dataless workstation is started remotely over a network. A
machine is started for normal operations with the key in the normal position.
One or more remote file servers provide the files and programs that diskless
or dataless workstations need to boot.
Service Boot
A machine is started from a hard disk, network, tape, or CD-ROM with the key
set in the service position. This condition is also called maintenance mode. In
maintenance mode, a system administrator can perform tasks, such as
installing new or updated software and running diagnostic checks.
During a hard disk boot, the boot image is found on a local disk created when the
operating system was installed. During the boot process, the system configures
all devices found in the machine and initializes other basic software required for
the system to operate (such as the Logical Volume Manager). At the end of this
process, the file systems are mounted and ready for use.
The same general requirements apply to diskless network clients. They also
require a boot image and access to the operating system file tree. Diskless
network clients have no local file systems and get all their information by way of
remote access.
The system finds all necessary information for the boot process on its disk drive.
When the system is started by turning on the power switch (a cold boot) or
restarted with the reboot or shutdown commands (a warm boot), a number of
events must occur before the system is ready for use. These events can be
divided into the following phases:
1. Read Only Storage (ROS) Kernel Init Phase
During this phase, problems with the motherboard are checked, and the ROS
initial program load searches for the bootlist. Once the bootlist is found, the
boot image is read into memory and system initialization starts.
2. Base Device Configuration Phase
All devices are configured in this phase, with the help of the cfgmgr command.
3. System Boot Phase
In this phase of the boot process, all the logical volumes are varied on, paging
is started, and the /etc/inittab file is processed.
14 IBM ^ Certification Study Guide - pSeries AIX System Administration
2.3 Power on sequence, LEDs, and audio signals
Several MCA based RS/6000 systems have LED displays to show what phase of
the boot process the system is going through. If something goes wrong, you can
interpret the LED codes and take the appropriate action to rectify the problem.
PCI RS/6000 systems use sounds and graphics to show the different phases of
the boot process. For example, as soon as you power on the system, an audio
beep is produced when the processor is found to be active, the PowerPC logo is
shown (or text is presented) when the system memory checking is completed,
and device logos are shown for all devices that have a valid address. At the end
of the device logo display, if the system ROS is not damaged, an audio beep is
again produced.
System administrators solve the problems that they might encounter during the
startup process using these indicators.
2.4 Useful commands
The commands that are used to manage system startup, shutdown, and the
related tasks are discussed in the following sections.
2.4.1 Using the alog command
There may be instances when you must trace the boot process and find out if
something went wrong with the system during the boot process. AIX provides
you with an excellent tool to monitor these problems through the help of the alog
command.
The alog command can maintain and manage logs. It reads standard input,
writes to standard output, and copies the output into a fixed-size file. This file is
treated as a circular log. If the file is full, new entries are written over the oldest
existing entries.
Tip: As a specialist, memorizing the error codes enables you to quickly get
to the heart of critical system problems. Therefore, it is one of the sections
of the exam that requires memorization.
Chapter 2. System startup problem handling 15
The rc.boot script explicitly redirects boot information through the alog command
to the file /var/adm/ras/bootlog. If something goes wrong with the system, you
can boot the system in single-user mode (maintenance mode) and access these
logs through the alog command to see at what stage the system is failing. A part
of the rc.boot script is shown below to illustrate how the logging mechanism has
been incorporated.
# Error Recovery if customized data is zero
[ -f /no_sbase ] && {
echo "rc.boot: executing savebase recovery procedures" \
>>/tmp/boot_log
X=`ODMDIR=/mnt/etc/objrepos odmshow CuDv |\
fgrep population`
count=`echo $X | cut -f2 -d' '`
[ $count -ne 0 ] && {
/usr/sbin/savebase -o /mnt/etc/objrepos
[ $? -ne 0 ] && loopled 0x546
mount /var# so that reboot can log
echo "savebase recovery reboot" \
>>/tmp/boot_log
cat /tmp/boot_log | alog -q -t boot
reboot
}
}
The alog command works with log files that are specified on the command line or
with logs that are defined in the alog configuration database.
The most common flags used with the alog command and their description are
given in Table 2-1.
Table 2-1 Command flags for alog
Flag Description
-f LogFile Specifies the name of a log file. If the specified LogFile does not exist,
one is created. If the alog command is unable to write to LogFile, it
writes to /dev/null.
-L Lists the log types currently defined in the alog configuration
database. If you use the -L flag with the -t LogType flag, the attributes
for a specified LogType are listed.
-o Lists the contents of LogFile; writes the contents of LogFile to
standard output in sequential order.
-q Copies standard input to LogFile, but does not write to standard
output.
16 IBM ^ Certification Study Guide - pSeries AIX System Administration
AIX logs can be maintained by using either SMIT or by using the alog command
directly. The general uses of the alog command are as follows:
Showing the contents of a log file
To list the contents of a log file, use the command:
alog -f LogFile -o
Logging data to a specified log file
You can change the default file that is used to log the activities by using the
following command:
alog -f LogFile | [ [ -q ] [ -s Size ] ]
Displaying the verbosity value of a specified log type
The verbosity value specifies the depth of information that is written to a log. In
order to display the verbosity value of a log, use the following command:
alog -t LogType -V
Changing the attributes of a specified log type
You can use the different attributes of a log type by using the following command:
alog -C -t LogType [ -f LogFile ] [ -s Size ] [ -w Verbosity ]
Displaying the current attributes of a specified log type
Before you can change the attributes of a log it is recommended to view what the
current attributes are. Use the following command to display the current
attributes of a log type:
alog -L [ -t LogType ]
To view the boot log, you can either use SMIT or use the alog command directly.
Follow the sequence in “Viewing the boot log” on page 17 to view the contents of
the boot log.
-t LogType Identifies a log defined in the alog configuration database. The alog
command gets the log's file name and size from the alog
configuration database.
Flag Description
Chapter 2. System startup problem handling 17
Viewing the boot log
You can view the boot log by either using the SMIT fast path smitty alog_show
and giving the name of the log you want to view, or you can use the alog
command. To view a log using the alog command, determine what predefined
logs are available to you.
Use the alog -L command to view the logs defined in the alog database. On the
command line enter:
# alog -L
boot
bosinst
nim
dumpsymp
To view the boot log (the log that holds boot information) enter:
# alog -o -t boot
---------
attempting to configure device 'fda0'
invoking /usr/lib/methods/cfgfda_isa -2 -l fda0
return code = 0
****************** stdout ***********
fd0
****************** no stderr ***********
-----------------------------------------------------------------------
invoking top level program -- "/etc/methods/starttty"
return code = 0
****************** no stdout ***********
****************** no stderr ***********
-----------------------------------------------------------------------
invoking top level program -- "/etc/methods/startsmt"
return code = 0
****************** no stdout ***********
****************** no stderr ***********
-----------------------------------------------------------------------
invoking top level program -- "/etc/methods/load_blockset_ext"
return code = 0
****************** no stdout ***********
****************** no stderr ***********
-----------------------------------------------------------------------
invoking top level program -- "/usr/lib/methods/defaio"
return code = 0
****************** no stdout ***********
****************** no stderr ***********
-----------------------------------------------------------------------
calling savebase
return code = 0
18 IBM ^ Certification Study Guide - pSeries AIX System Administration
****************** no stdout ***********
****************** no stderr ***********
Starting AIX Windows Desktop.....
Saving Base Customize Data to boot disk
Starting the sync daemon
Starting the error daemon
System initialization completed.
Starting Multi-user Initialization
Performing auto-varyon of Volume Groups
Activating all paging spaces
swapon: Paging device /dev/hd6 activated.
/dev/rhd1 (/home): ** Unmounted cleanly - Check suppressed
Performing all automatic mounts
Multi-user initialization completed
Any errors that are encountered will be logged into this file. However, the alog file
has no concurrency control; therefore, if multiple processes try to write to the
same file at the same time, the contents of the log file might not be as
anticipated. Additionally, it is a cyclic file; so, when its size reaches the maximum,
it is overwritten.
2.4.2 Using the cfgmgr command
During the boot process, the system has to determine what resources are
available to it. For example, the system has to determine what kind of bus the
system is using, what type of devices are attached to the system, where the
rootvg resides, and so on. The configuration of these devices is handled by the
BOS command cfgmgr. The cfgmgr command configures devices and optionally
installs device software into the system.
The general syntax of the cfgmgr command is as follows:
cfgmgr [ -f | -s | -p Phase ] [ -i Device ] [ -l Name ] [ -v ]
The most commonly used flags and their description are given in Table 2-2:
Table 2-2 Command flags for cfgmgr
Flag Description
-f Specifies that the cfgmgr command runs the phase 1 configuration
rules. This flag is not valid at run time (after system start).
-i Device Specifies the location of the installation medium.
-l Name Specifies the named device to configure along with its children.
-p Phase Specifies the phase that the cfgmgr command runs.
Chapter 2. System startup problem handling 19
The devices to be configured are controlled by the Configuration Rules object
class, which is part of the Device Configuration database. Each configuration rule
specifies three items:
The full path name of an executable program to run.
When to run the program (in relation to the other rules).
In which phase to run the program.
During system boot, the cfgmgr command configures all the devices that are
necessary to use the system. System boot consists of two phases.
Phase 1
Phase 1 begins when the kernel is brought into the system, and the boot file
system is initialized. During this phase, the cfgmgr command is invoked,
specifying this as phase 1 by using the -f flag. The cfgmgr command runs all
of the phase 1 configuration rules, which results in the base devices being
configured.
Phase 2
In this phase, the cfgmgr command is called with the -s flag.
The cfgmgr command recognizes three phases of configuration rules:
Phase 1
Phase 2 (second boot phase for normal boot)
Phase 3 (second boot phase for service boot)
Normally, the cfgmgr command runs all the rules for the phase specified during
invocation (for example, phase 1 rules for the -f flag). However, if the -l flag is
issued, the cfgmgr command configures only the named device and its children.
If the cfgmgr command is invoked without a phase option (for example, without
the -f,-s, or -p flags), then the command runs the phase 2 rules. The only way to
run the phase 3 rules is with the -p flag.
-s Specifies that the cfgmgr command follows the phase 2 configuration
rules.
-v Specifies verbose output. The cfgmgr command writes information
about what it is doing to standard output.
Flag Description
20 IBM ^ Certification Study Guide - pSeries AIX System Administration
If you invoke the cfgmgr command with the -i flag, the command attempts to
install device software automatically for each new detected device. The device
variable of the -i flag specifies where to find the installation medium. The
installation medium can be a hardware device (such as a tape or diskette drive),
a directory that contains installation images, or the installation image file itself.
The cfgmgr command configures only those devices at the system startup that
are powered on and are self configurable, such as SCSI drives or TTYs that have
been defined in the inittab file. If you have some devices that were not powered
on when the system started, the system will not make them available until you
explicitly tell it to configure them. The syntax of the command is:
cfgmgr -v
It will produce an output similar to the alog -o -t boot command. See
Section 3.2, “Configuring system devices” on page 45 for additional configuration
information.
2.4.3 Using the last command
The last command is generally used to display, in reverse chronological order,
all previous logins and logoffs recorded in the /var/adm/wtmp file. The
/var/adm/wtmp file collects login and logout records as these events occur and
retains them until the records are processed by the acctcon1 and acctcon2
commands as part of the daily reporting procedures. When the time daemon,
timed, changes the system time, it logs entries in wtmp under the pseudo-user
date. An entry starting with date | is logged before the change, and an entry
starting with date { is logged after the change. This allows for accurate
accounting of logins that span a time change. The general syntax of the
command is as follows:
last [ -f FileName ] [ -Number ] [ Name ... ] [ Ter min al ... ]
The common flags used with the last command are provided in Table 2-3.
Table 2-3 Command flags for last
Important: To protect the configuration database, the cfgmgr command is
not interruptible. Stopping this command before execution is complete
could result in a corrupted database.
Flag Description
-Number The number of lines to display in the output.
Name Logins and logouts of the users specified by the name parameter.
Chapter 2. System startup problem handling 21
For example, if you want to find out when the user root logged on and off from the
console, enter the command:
# last root console
root pts/3 dummy Oct 23 12:27 still logged in.
root lft0 Oct 22 11:45 still logged in.
root lft0 Oct 22 09:46 - 11:27 (01:40)
root pts/0 dummy Oct 21 11:36 - System is halted by
system administrator. (00:24)
root pts/1 dummy.xyz.abc Aug 08 13:05 - System is halted by
system administrator. (02:17)
root pts/0 dummy.xyz.abc Aug 08 12:43 - System is halted by
system administrator. (02:39)
root lft0 Sep 18 15:41 - System halted
abnormally. (14203+20:56)
root pts/1 dummy.xyz.abc Sep 18 15:00 - System halted
abnormally. (00:31)
root pts/3 dummy.xyz.abc Sep 18 12:05 - System halted
abnormally. (14245+02:51)
root pts/3 dummy.xyz.abc Sep 18 12:04 - 12:05 (00:00)
root pts/1 dummy.xyz.abc Sep 18 11:50 - 12:04 (00:14)
root pts/1 dummy.xyz.abc Sep 16 13:32 - 11:11 (1+21:38)
root pts/2 dummy.xyz.abc Sep 16 11:35 - System is halted by
system administrator. (00:04)
root pts/0 dummy.xyz.abc Sep 04 15:27 - System is halted by
system administrator. (00:15)
root lft0 Sep 04 15:27 - 15:40 (00:13)
wtmp begins Sep 04 15:11
The last command can also be used to determine when the system was last
shut down. The syntax of the command follows:
# last shutdown
shutdown pts/0 Oct 22 09:23
shutdown lft0 Oct 21 16:39
shutdown pts/0 Oct 21 13:41
shutdown lft0 Sep 25 14:43
shutdown pts/1 Aug 08 15:22
shutdown lft0 Sep 16 11:40
shutdown ~ Sep 08 14:47
Ter min al Login and logoffs from the terminals specified by the terminal
parameter.
Flag Description
22 IBM ^ Certification Study Guide - pSeries AIX System Administration
2.4.4 Using the bootlist command
The bootlist command allows you to display and alter the list of boot devices
from which the system may be booted. When the system is booted, it will scan
the devices in the list and attempt to boot from the first device it finds containing a
boot image. This command supports updating of the following:
Normal boot list The normal list designates possible boot devices for
when the system is booted in normal mode.
Service boot list The service list designates possible boot devices for
when the system is booted in service mode.
Previous boot device This entry designates the last device from which the
system booted. Some hardware platforms may attempt
to boot from the previous boot device before looking for a
boot device in one of the other lists.
Support of these boot lists varies from platform to platform. Some platforms do
not have boot lists. When searching for a boot device, the system selects the first
device in the list and determines if it is bootable. If no boot file system is detected
on the first device, the system moves on to the next device in the list. As a result,
the ordering of devices in the device list is extremely important.
The general syntax of the command is as follows:
bootlist [ { -m Mode } [ -r ] [ -o ] [ [ -i ] |
[ [ -f File ] [ Device [ Attr=Value ... ] ... ] ] ]
The most common flags used with the bootlist command are provided in
Tabl e 2-4.
Table 2-4 Command flags for bootlist
Flag Description
-m mode Specifies which boot list to display or alter. Possible values for the
mode variable are normal, service, both, or prevboot.
-f File Indicates that the device information is to be read from the specified
file name.
-i Indicates that the device list specified by the -m flag should be
invalidated.
-o Displays bootlist with the -m flag. Applies only to AIX Version 4.2 or
later.
-r Indicates whether to display the specified bootlist after any specified
alteration is performed.
Chapter 2. System startup problem handling 23
To display a boot list (AIX Version 4.2 or later) use the command:
# bootlist -m normal -o
fd0
cd0
hdisk0
If you want to make changes to your normal boot list, use the command:
bootlist -m normal hdisk0 cd0
This will change the normal bootlist to indicate that when the system is booted, it
will first attempt to boot from hdisk0. If it cannot find a boot image in hdisk0 it will
search the CD-ROM. Otherwise, it will instruct the system to provide an LED
error code and wait for user intervention.
Boot device choices
The naming conventions that can be used in your boot list are provided in
Table 2-5. Each device that you add to your bootlist must be in the AVAILABLE
state. Otherwise, the bootlist command will fail, and you will encounter an error
similar to:
0514-210 bootlist: Device xxxxx is not in the AVAILABLE state
Table 2-5 Valid device names for the bootlist command
2.4.5 Using the uptime command
If you suspect that your system was shutdown and restarted, you can use the
uptime command to find this out. The uptime command shows how long the
system has been up. The general syntax of the command is as follows:
# uptime
05:10PM up 6 days, 21:45, 13 users, load average 4.00, 3.00, 0.00
Device Description
fdxx Diskette drive device logical names
hdiskxx Physical volume device logical names
cdxx SCSI CD-ROM device logical names
rmtxx Magnetic tape device logical names
entxx Ethernet adapter logical names
tokxx Token ring adapters logical names
24 IBM ^ Certification Study Guide - pSeries AIX System Administration
The uptime command prints the current time, the length of time the system has
been up, the number of users online, and the load average. The load average is
the number of runnable processes over the preceding 5, 10, or 15 minute
intervals. The output of the uptime command is, essentially, the heading line
provided by the w command.
2.4.6 Using the mpcfg command
The mpcfg command enables a user with root authority to manage service
information consisting of the service support and diagnostic flags (-S and -f
flags), the modem and site configuration (-m flag), and the remote support phone
numbers (-p flag).
The mpcfg command works only on multiprocessor systems with Micro Channel
I/O. For IBM systems, this includes the IBM 7012 Model G Series, the IBM 7013
Model J Series, and the IBM 7015 Model R Series.
The general syntax of the command and the meaning of the flags are as follows:
Display service information
To display service information, you can use:
mpcfg -d { -f -m -p -S}
For example, To find out what the status is of your diagnostic flags, use the mpcfg
command as shown in Figure 2-1 on page 25.
Tip: The discussion about Micro Channel I/O may seem out of date now
that PCI is used in every RS/6000 product, but many of the older Micro
Channel machines are still in use and require specific skills. A specialist
should know how to configure new and old hardware.
Chapter 2. System startup problem handling 25
Figure 2-1 Displaying diagnostic flags
Change service information
To change the service information, use the mpcfg command with the following
combination of flags:
mpcfg -c { -f | -m | -p -S -w} Index Value...
For example, if you want to fast IPL the system, you can change the value of the
diagnostic flag as follows:
mpcfg -cf 11 1
This command will search the index (see Figure 2-1 on page 25) and change the
value of the eleventh item (Fast IPL) to 1. The next time the system is booted, the
system will skip the extensive hardware testing and take less time to boot than
normal.
Save or restore service information
To store information about the flags, use the mpcfg command with the following
syntax:
mpcfg { -r | -s }
26 IBM ^ Certification Study Guide - pSeries AIX System Administration
The most commonly used command flags for the mpcfg command are listed in
Tabl e 2-6.
Table 2-6 Command flags for mpcfg
2.4.7 Using the shutdown command
A system shutdown is controlled by a shell script that properly prepares a system
with multiple users to be turned off or rebooted. An improper shutdown can have
undesirable results on the system’s integrity.
The general syntax of the shutdown command is as follows:
shutdown [ -d ] [ -F ] [ -h ] [ -i ] [ -k ] [ -m ] [ -p ] [ -r ]
[ -t mmddHHMM [ yy ] ] [ -v ] [ +Time [ Message ] ]
The common flags used with the shutdown command are provided in Table 2-7.
Table 2-7 Command flags for shutdown
Flag Description
-c Changes the values of service information. The values that you want
to modify are identified first by the flag -f, -m, -p, or -S, and then by
their index (Index parameter) within this category.
-d Displays the values of service information according to the -f, -m, -p,
and -S flags set in the command. These values are displayed
associated with their corresponding indexes and names.
-s Saves the service information in the /etc/lpp/diagnostics/data/bump
file.
-f Indicates that the action (display or change) will be applied to the
diagnostic flags.
-m Indicates that the action (display or change) will be applied to the
modem and site configuration.
-p Indicates that the action (display or change) will be applied to the
remote support phone numbers.
-S Indicates that the action (display or change) will be applied to the
service support flags.
-w Indicates that the change will be applied to a password.
Flag Description
-d Brings the system down from a distributed mode to a multiuser mode.
Chapter 2. System startup problem handling 27
To perform a fast shutdown and restart the system, enter:
shutdown -Fr
You will see the message
shutdown completed.
at the end of this process before the reboot.
Adding applications to the shutdown process
At times, it may be necessary to properly close down all the applications and
other user processes without issuing a kill command to end the processes. You
can achieve this by adding your desired commands and actions to a file named
/etc/rc.shutdown. The /etc/rc.shutdown file is checked each time a shutdown
command is issued. If the file exists, it will be run; otherwise, the system will
perform a regular shutdown depending on the flags that are used to bring the
system down.
Beginning with AIX Version 4.2.0, the /usr/sbin/shutdown script is changed to
incorporate this file. A part of the /usr/sbin/shutdown script executing the
rc.shutdown file is shown below:
if [ $nohalt = off ]
then
# /etc/rc.shutdown is for administrators to create for their
# own local needs. If it is not successful, shutdown will
-F Does a fast shutdown, bypassing the messages to other users, and
brings the system down as quickly as possible.
-h Halts the operating system completely; it is the same as the -v flag.
-i Specifies interactive mode. Displays interactive messages to guide
the user through the shutdown.
-k Avoids shutting down the system.
-m Brings the system down to maintenance (single user) mode.
-r Restarts the system after being shutdown with the reboot command.
-v Halts the operating system completely.
Flag Description
Tip: /etc/rc.shutdown must be set as executable before it can called by the
/usr/sbin/shutdown script.
28 IBM ^ Certification Study Guide - pSeries AIX System Administration
# abort.
if [ -x /etc/rc.shutdown ]
then
sh /etc/rc.shutdown
if [ $? -ne 0 ] ; then
dspmsg -s 1 shutdown.cat 60 \
"/etc/rc.shutdown failed. Shutdown aborting.\n"
exit 1
fi
fi
2.5 Troubleshooting boot problems
There are many contributing factors towards a system failure.
Due to mishandling, for example, if someone intentionally accesses and ends
up corrupting it.
When conditions, such as a power failure, corrupt the Boot Logical Volume
(BLV).
When a disk encounters many bad blocks under which the system becomes
un-usable.
Any of these conditions may prevent the system from restarting.
The sections that follow contain a discussion of the situations where the system
will not boot and how to correct the problems.
2.5.1 Accessing a system that will not boot
If you are unable to boot your system, the first step is to access the system and
see what is the probable cause of the failure. This procedure enables you to get a
system prompt so that you may attempt to recover data from the system or
perform corrective action that will enable the system to boot from the hard disk.
The following steps summarize the procedure for accessing a system that will not
boot. For detailed information, see the AIX Installation Guide.
To access the system:
1. Turn on all attached external devices, such as terminals, CD-ROM drives,
tape drives, monitors, and external disk drives before turning on the system
unit. Turn on the system unit to allow the installation media to be loaded.
Tip: You must have root authority to perform all of these functions.
Chapter 2. System startup problem handling 29
2. Insert Volume 1 of the installation media into the tape or CD-ROM drive and
power the system unit off.
3. Turn the system key (if present) to the service position or alternatively press
F5 (or 5) on PCI-based systems to boot from the tape or CD-ROM drive
(during step 4).
4. Turn the system unit power switch to the on position. When booting from
alternate media, a screen will appear (before the one in Figure 2-2) asking
you to press a function key (such as F1) to select the proper display as the
system console. Each display attached to the system will receive a function
key number to identify it as the system console. The system begins booting
from the installation media. After several minutes, C31 is displayed in the LED
(if your system has an LED; otherwise, a screen similar to the one in
Figure 2-2 is shown).
Figure 2-2 Welcome to BOS Installation and Maintenance menu
5. Select option 3, Start Maintenance Mode for System Recovery, and press
Enter. A screen similar to Figure 2-3 on page 30 is shown.
Welcome to Base Operating System
Installation and Maintenance
Type the number of your choice and press Enter.
>>> 1 Start Installation Now with Default Settings
2 Change/Show Installation Settings and Install
3 Start Maintenance Mode for System Recovery
88 Help ?
Choice [1]:
99 Previous Menu
30 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 2-3 Maintenance menu
6. Choose 1, Access a Root Volume Group. A screen similar to Figure 2-4 is
shown.
Figure 2-4 Warning message window
7. Enter a 0 (zero), and press Enter. A screen similar to Figure 2-5 on page 31 is
shown.
Maintenance
Type the number of your choice and press Enter.
>>> 1 Access a Root Volume Group
2 Copy a System Dump to Removable Media
3 Access Advanced Maintenance Functions
4 Install from a System Backup
88 Help ?
99 Previous Menu
>>> Choice [1]:
88 Help ?
>>> 99 Previous Menu
>>> Choice [99]:
Warning
If you choose to access a root volume group, you will not be able to return
to the Base Operating System Installation menus without rebooting.
Type the number of your choice and press Enter
0 Continue
Chapter 2. System startup problem handling 31
Figure 2-5 Access a Root Volume Group menu
8. Select the volume group whose logical volume information you want to
display. This is important because rootvg will contain hd5 (the boot logical
volume). Enter the number of the volume group and press Enter. A screen
similar to Figure 2-6 is shown.
Figure 2-6 Volume Group Information menu
Choice:
Access a Root Volume Group
information and press Enter.
1) Volume Group 00615147b27f2b40 contains these disks:
hdisk0 958 04-B0-00-2,0
2) Volume Group 00615247b27c2b41 contains these disks:
hdisk1 2063 04-B0-00-6,0
Type the number for a volume group to display logical volume
Volume Group ID 00615147b27f2b40 includes following logical volumes:
Volume Group Information
hd5 hd6 hd8 hd4 hd2 hd9var
hd3 hd1 lv00 lv01
Type the number of your choice and press Enter.
1) Access this Volume Group and start a shell
2) Access this Volume Group and start a shell before mounting file systems
99) Previous Menu
Choice [99]:
32 IBM ^ Certification Study Guide - pSeries AIX System Administration
9. Select one of the options from the Volume Group Information screen and
press Enter. Each option does the following:
Choice 1 Access this volume group and start a shell.
Selecting this choice imports and activates the volume group
and mounts the file systems for this root volume group before
providing you with a shell and a system prompt.
Choice 2 Access this volume group and start a shell before mounting file
systems.
Selecting this choice imports and activates the volume group
and provides you with a shell and system prompt before
mounting the file systems for this root volume group.
Choice 99 Entering 99 returns you to the Access a Root Volume Group
screen.
After either choice 1 or 2 is selected and processed, a shell is started and a
system prompt is displayed.
10.Take the appropriate measures to recover data or take additional action (such
as using the bosboot command) to enable the system to boot normally.
2.5.2 Problems with installation media
If you are installing a new system or performing a migration installation to a
newer version of AIX, you may run into problems with the installation media.
Some symptoms of installation media problems include unexpected halts during
installation, failure to read information from the media, or unexpected system
reboots. The following steps summarize the procedure for determining
installation media problems:
1. Confirm that all attached external devices, such as terminals, CD-ROM
drives, tape drives, monitors, and external disk drives, are powered on before
turning on the system unit. Turning external units on after turning on the
system unit can prevent external units from operating or sending information
to the system unit. For example, turning on a SCSI CD-ROM for system
installation after the system unit has been turned on may make the CD-ROM
inoperative.
2. Visually inspect the media for physical damage. For example, a CD-ROM with
scratches on it may not be read properly by the CD-ROM drive. Or, a tape
drive with ribbon hanging out the front of the cartridge may not function
properly in the tape drive. Installation media that has physical damage should
not be used for installation and should be set aside or thrown away.
Chapter 2. System startup problem handling 33
3. Confirm that all installation options are properly set before installation. If you
are attempting an installation and choose options that provide the system with
incorrect commands or configuration, the system may not perform the
installation as it should. For example, if you tell the system to install the BOS
to a disk that is too small to hold the BOS, your installation may not complete.
4. Attempt the installation using another set of media, if the installation process
is not working. Your media may be defective due to wear and tear,
manufacturing defect, or environmental factors. Obtain another copy of the
installation media and repeat the installation process.
5. Confirm that all hardware is functioning properly. If the installation media is
functioning properly on another system, but your installation fails on your
system, there may be a hardware problem. Check all external cables and
ensure that hardware is properly configured. For example, two devices on
your system may be sharing the same SCSI address, which could halt an
installation. If problems persist, use a diagnostics disk for analysis or contact
your local customer engineer for hardware support.
2.5.3 Common boot time LED error codes and recovery actions
The most common boot problems and methods to get your system up and
running again are given in Table 2-8.
Table 2-8 Common startup LEDs and recovery actions
LED 201 - Damaged boot image
1. Access your rootvg following the procedure described in Section 2.5.1, “Accessing
a system that will not boot” on page 28.
2. Check the / and /tmp file systems. If they are almost full, create more space.
3. Determine the boot disk by using the command: lslv -m hd5
4. Re-create boot image using: bosboot -a -d /dev/hdiskn
5. Check for CHECKSTOP errors in the error log. If such errors are found, it is
probably failing hardware.
6. Shutdown and restart the system.
34 IBM ^ Certification Study Guide - pSeries AIX System Administration
LED 223-229 - Invalid boot list
1. Set the key mode switch to service (F5 for systems without a keylock) and power up
the machine.
2. If the display continues normally, change the key mode switch to Normal and
continue with step 3. If you do not get the prompt, go to step 4.
3. When you get the login prompt, log in and follow the procedure described in
Section 2.4.4, “Using the bootlist command” on page 22 to change your bootlist.
Continue with step 7.
4. Follow the procedure in Section 2.5.1, “Accessing a system that will not boot” on
page 28 to access your rootvg and continue with step 5.
5. Determine the boot disk by using the command: lslv -m hd5
6. Change the bootlist following the procedure given in Section 2.4.4, “Using the
bootlist command” on page 22.
7. Shutdown and restart your system.
LED 551, 555, and 557 - Errors including corrupted file system and corrupted JFS
log
1. Follow the procedure described in Section 2.5.1, “Accessing a system that will not
boot” on page 28, to access the rootvg before mounting any file systems (Option 2
on the Maintenance screen).
2. Verify and correct the file systems as follows:
fsck -y /dev/hd1
fsck -y /dev/hd2
fsck -y /dev/hd3
fsck -y /dev/hd4
fsck -y /dev/hd9var
3. Format the JFS log again by using the command:
/usr/sbin/logform /dev/hd8
4. Use lslv -m hd5 to determine the boot disk.
5. Recreate boot image by using the command:
bosboot -a -d /dev/hdiskn
Where n is the disk number of the disk containing the boot logical volume.
Chapter 2. System startup problem handling 35
Led 552, 554, and 556 - Super block corrupted
or corrupted customized ODM database
1. Repeat steps 1 and 2 for LEDs 551, 555, and 557.
2. If fsck indicates that block 8 is corrupted, the super block for the file system is
corrupted and needs to be repaired. Enter the command:
dd count=1 bs=4k skip=31 seek=1 if=/dev/hdn of=/dev/hdn
where n is the number of the file system.
3. Rebuild your JFS log by using the command:
/usr/sbin/logform /dev/hd8
4. If this solves the problem, stop here; otherwise, continue with step 5.
5. Your ODM database is corrupted. Restart your system and follow the procedure
given in Section 2.5.1, “Accessing a system that will not boot” on page 28 to access
rootvg with Choice 2.
6. Mount the root and usr file system as follows:
mount /dev/hd4 /mnt
mount /usr
7. Copy system configuration to a backup directory:
mkdir /mnt/etc/objrepos/backup
cp /mnt/etc/objrepos/Cu* /mnt/etc/objrepos/backup
8. Copy configuration from RAM file system as follows:
cp /etc/objrepos/Cu* /mnt/etc/objrepos
9. Unmount all file systems by using the umount all command.
10. Determine boot disk by using the lslv -m hd5 command.
11. Save the clean ODM to the boot logical volume by using the command:
savebase -d/dev/hdiskn
12. Reboot the system. If system does not come up, reinstall BOS.
36 IBM ^ Certification Study Guide - pSeries AIX System Administration
2.6 Quiz
The following are questions created by the authors to further test your
understanding of the topics.
1. A system administrator suspects that a colleague rebooted their server the
previous evening. Which of the following commands will confirm this
suspicion?
A. uptime
B. lastboot
C. reboot -l
D. bootinfo -t
2. Once the machine has been powered on, which of the following is the correct
way to reach the Systems Management Services menu on a PCI machine?
A. Press the space-bar when the LED displays 262.
B. Turn the key to Service mode when the LED displays 200.
C. Choose SMS when the boot option menu appears on screen.
D. Press the appropriate function key once the keyboard has been enabled.
LED 553 - Corrupted /etc/inittab file
1. Access the rootvg with all file systems mounted by following the procedure
described in Section 2.5.1, “Accessing a system that will not boot” on page 28.
2. Check for free space in /, /var, and /tmp by using the df command.
3. Check the /etc/inittab file and correct the inittab problems, such as an empty inittab
file, a missing inittab file, or a wrong entry in the inittab file.
4. Check for execution problems with:
/etc/environment
/bin/sh
/bin/bsh
/etc/fsck
/etc/profile
/.profile
5. Shutdown the system and reboot.
Chapter 2. System startup problem handling 37
3. While attempting a preservation install, all of the hardware connections
appear to be correct. However, when trying to boot from CD-ROM, the
machine ends up in diagnostics. Which of the following is the most likely
cause of this problem?
A. The battery on the machine is bad.
B. The root volume group is corrupt.
C. The low-level debugger is not enabled.
D. There is a hardware problem with the CD-ROM.
2.6.1 Answers
The following answers are for the quiz questions.
1. A
2. D
3. D
2.7 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Change your bootlist to boot over the network over your token ring adapter on
the next system boot up.
2. Use the alog command to find out what events took place during your startup
process.
3. Shutdown and restart your system using the shutdown command.
4. You have just powered on an external tape drive. Use cfgmgr to bring that
tape drive into an available state and ensure that you see all the messages
with the cfgmgr command.
5. Add an application to your shutdown process that gracefully brings down your
running databases.
6. Find out the amount of time your system has been online.
7. Find out when root last logged onto the system and from which terminal.
8. Use the mpcfg command to change your Fast IPL flag to true.
38 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 39
Chapter 3. Hardware assistance
This chapter discusses various methods to determine the devices installed on
your system, the methods available to you to record the system error messages,
and then ways of using these messages to solve system problems. It also
discusses using the system log to record any desired messages.
3
40 IBM ^ Certification Study Guide - pSeries AIX System Administration
3.1 Listing hardware devices
To learn about the hardware characteristics of your system, you can use the
following commands:
lsdev Displays devices on the system and their characteristics.
lspv Displays information about a physical volume within a volume group.
lsattr Displays information about the attributes of a given device or kind of
device.
For example:
To list the tapes on your system, use the lsdev -C -c tape command.
To list the disks on your system, use the lsdev -C -c disk command.
3.1.1 Using the lsdev command
You can use the lsdev command to display information about devices in the
device configuration database. You can use this command to display information
from either the Customized Devices object class in ODM using the -C flag or the
Predefined Devices object class in ODM using the -P flag. For more information
on the ODM, see Chapter 5, “Object Data Manager” on page 117.
The general command syntax of the lsdev command is as follows:
lsdev -C [ -c Class ] [ -s Subclass ] [ -t Type ] [ -f File ]
[ -F Format | -r ColumnName ] [ -h ] [ -H ] [ -l Name ]
[ -S State ]
lsdev -P [-c Class ] [ -s Subclass ] [ -t Type ] [ -f File ]
[ -F Format | -r ColumnName ] [ -h ] [ -H ]
Some of the commonly used flags with the lsdev command are provided in
Tabl e 3-1.
Table 3-1 lsdev command flags
Flag Description
-C Lists information about a device that is in the Customized Devices
object class. The default information displayed is name, status,
location, and description. This flag cannot be used with the -P flag.
-c Class Specifies a device class name. This flag can be used to restrict output
to devices in a specified class.
-H Displays headers above the column output.
-h Displays the command usage message.
Chapter 3. Hardware assistance 41
Following are some examples of using the lsdev command to list different device
information about a system.
Listing devices in the predefined ODM database
To list all devices in the Predefined Devices object class with column headers, on
the command line, enter:
lsdev -P -H
The system displays an output similar to Figure 3-1.
Figure 3-1 Listing devices from a pre-defined ODM database
-P Lists information about a device that is in the Predefined Devices
object class. The default information displayed is class, type,
subclass, description. This flag cannot be used with the -C, -l, or -S
flags.
-S State Lists all devices in a specified state as named by the State parameter.
Flag Description
42 IBM ^ Certification Study Guide - pSeries AIX System Administration
Listing devices in customized ODM database
To list all the devices in the Customized Devices object class, enter:
lsdev -C -H
An output similar to Figure 3-2 is shown:
Figure 3-2 Listing devices in the customized ODM database
Listing available devices
To list the adapters that are in the Available state in the Customized Devices
object class, enter:
lsdev -C -c adapter -S a
An output similar to Figure 3-3 is shown:
Figure 3-3 Listing available devices
Chapter 3. Hardware assistance 43
Listing supported devices
To list all the classes of supported devices on your system, on the command line
enter:
lsdev -P -r class
An output similar to Figure 3-4 is shown:
Figure 3-4 Listing supported devices
3.1.2 Using the lspv command
The lsdev command obtains general information about the devices installed on
your system; however, you can find out specific information about your physical
volumes using the lspv command.
If you do not use command flags with the lspv command, the default is to provide
every known physical volume on the system along with its physical disk name,
physical volume identifiers (PVIDs), and which volume group (if any) it belongs
to. If you specify the lspv command with a physical volume name, it displays
information about that physical volume only. The general syntax of the lspv
command is as follows:
lspv [ -l | -p | -M ] [ -n DescriptorPhysicalVolume] [-vVolumeGroupID]
PhysicalVolume
44 IBM ^ Certification Study Guide - pSeries AIX System Administration
Two of the most commonly used flags with the lspv command are given in
Tabl e 3-2.
Table 3-2 lspv command flags
For example, to display the physical volumes on your system, enter:
#lspv
hdisk0 00615147ce54a7ee rootvg
hdisk1 00615147a877976a rootvg
To display the status and characteristics of physical volume hdisk0, use the lspv
command as follows:
lspv hdisk0
An output similar to Figure 3-5 is shown:
Figure 3-5 Listing physical volume characteristics
To list the status and characteristics of physical volume hdisk0 by physical
partition number, use the lspv command as follows:
lspv -p hdisk0
Flag Description
-p Lists range, state, region, LV name, type, and mount point for
each physical partition on the physical volume.
-v VolumeGroupID Accesses information based on the VolumeGroupID variable.
Chapter 3. Hardware assistance 45
A screen similar to Figure 3-6 is shown:
Figure 3-6 Listing physical volume characteristics by physical partitions
3.2 Configuring system devices
When you add a new device to your system, or you need to configure devices
that were not detected as available during the boot process, the system must
have a way of configuring these devices. The cfgmgr command is used to
configure devices and, optionally, install device software into the system. The
devices to be configured are controlled by the Configuration Rules object class,
which is part of the Device Configuration database. Each configuration rule
specifies three items:
The full path name of an executable program to run.
When to run the program (in relation to the other rules).
In which phase to run the program.
During system boot, the cfgmgr command configures all the devices that are
necessary.
The cfgmgr command recognizes three phases of configuration rules:
Phase 1
Phase 2 (second boot phase for normal boot)
Phase 3 (second boot phase for service boot)
46 IBM ^ Certification Study Guide - pSeries AIX System Administration
During Phase 1, the cfgmgr command is invoked specifying this as Phase 1 by
using the -f flag. The cfgmgr command runs all of the Phase 1 configuration
rules, which results in the base devices being configured. After this, Phase 2
execution begins, and the cfgmgr command is called with the -s flag.
Normally, the cfgmgr command runs all the rules for the phase specified during
invocation (Phase 1 rules for the -f flag). However, if the -l flag is used, the cfgmgr
command configures only the named device and its children.
If the cfgmgr command is invoked without a phase option (for example, without
the -f,-s, or -p flags), then the command runs the Phase 2 rules. The only way to
run the Phase 3 rules is with the -p flag.
The configuration rules for each phase are ordered based on the values specified
in the
seq field. This field is an integer that specifies the priority in which to
execute this rule relative to the other rules for this phase. The higher the number
specified by the seq field, the lower the priority; for example, a value of 1
specified in the seq field is run before a rule with a value of 10. There is one
exception: A seq field value of 0 implies a
don't care condition, and any seq
field value of 0 is executed last.
Therefore, a seq field value of 1 is the highest priority (first to run).
If there are any devices detected that have no device software installed while
configuring devices, the cfgmgr command returns a warning message with the
name or a list of possible names for the device package that must be installed. If
the specific name of the device package is determined, it is displayed as the only
package name on a line below the warning message. If the specific name cannot
be determined, a colon-separated list of possible package names is displayed on
a single line. A package name or list of possible package names is displayed for
each of the devices if more than one device is detected without its device
software.
An example is as follows:
cfgmgr: 0514-621 WARNING: The following device packages are
required for device support but are not currently
installed.
devices.pci.22100020
devices.pci.14101800
devices.pci.scsi:devices.pci.00100300:devices.pci.NCR.53C825
In this example, two devices were found whose software is missing, and the
cfgmgr command displayed the names of the device packages that must be
installed. A third device whose software is missing was also found but in this
case, the cfgmgr command displays several possible device package names.
Chapter 3. Hardware assistance 47
When more than one possible package name is identified for a device, typically
only one of the names will correspond to a device package on the installation
medium. This is the package to install. However, in some cases, more than one
of the names will correspond to device packages on the installation medium. In
this case, the first package name in the list, for which there is an actual device
package on the installation medium, is the package that must be installed. If the
cfgmgr command is used with the -i flag, then the correct packages will be
installed.
If you invoke the cfgmgr command with the -i flag, the command attempts to
install device software automatically for each newly detected device. The device
variable of the -i flag specifies where to find the installation medium. The
installation medium can be a hardware device (such as a tape or diskette drive),
a directory that contains installation images, or the installation image file itself.
Some of the common flags used with the cfgmgr command are provided in
Tabl e 3-3.
Table 3-3 cfgmgr command flags
The configuration rules used by the cfgmgr command are provided in Table 3-4.
Table 3-4 cfgmgr configuration rules
Flag Description
-i Device Specifies the location of the installation medium.
-l Name Instructs the named device to be configured along with its children.
-p Phase Instructs the cfgmgr command to run the specified phase.
-s Instructs the cfgmgr command to run the Phase 2 configuration rules.
-v Specifies the type of details to be written to stdout.
Rule Description
phase Specifies whether this rule belongs to Phase 1, Phase 2, or Phase 3
(second boot phase for the service mode).
seq Specifies, as an integer, the relative priority of this rule.
rule A string containing the full path name of a program to run (can also
contain any flags, but they must follow the program name, as this
whole string is run as though it were typed in on the command line).
48 IBM ^ Certification Study Guide - pSeries AIX System Administration
The following examples are based on the configuration rules containing the
following information:
phase seq rule
1 1 /usr/lib/methods/defsys
1 10 /usr/lib/methods/deflvm
2 1 /usr/lib/methods/defsys
2 5 /usr/lib/methods/ptynode
2 10 /usr/lib/methods/startlft
2 15 /usr/lib/methods/starttty
3 1 /usr/lib/methods/defsys
3 5 /usr/lib/methods/ptynode
3 10 /usr/lib/methods/startlft
3 15 /usr/lib/methods/starttty
When the cfgmgr command is invoked with the -f flag, the command reads all of
the configuration rules with phase = 1 and runs them in the following order:
/usr/lib/methods/defsys
/usr/lib/methods/deflvm
When the cfgmgr command is run with the -s flag, the command reads all of the
configuration rules with phase = 2 and runs them in the following order:
/usr/lib/methods/defsys
/usr/lib/methods/ptynode
/usr/lib/methods/startlft
/usr/lib/methods/starttty
When the cfgmgr command is run with the -p 3 flag, the command reads all of the
configuration rules with phase = 3 and runs them in the following order:
/usr/lib/methods/defsys
/usr/lib/methods/ptynode
/usr/lib/methods/startlft
/usr/lib/methods/starttty
If the cfgmgr command is run without a flag, the command functions the same as
when used with the -s flag. To configure detected devices attached to the SCSI0
adapter, use the cfgmgr command as follows:
cfgmgr -l scsi0
To install device software automatically during configuration (with the software
contained in a directory), use the cfgmgr command as follows:
cfgmgr -i /usr/sys/inst.images
Note: The -f flag cannot be used once the system has booted.
Chapter 3. Hardware assistance 49
3.3 System management services
The cfgmgr command configures devices at the software level. You can use the
System Management Services (SMS) to check and configure the system at a
hardware level. With SMS, you can check to see if all available hardware has
been detected, or you can test certain hardware for failure.
To access the SMS utility, use the following instructions:
1. Begin with your machine turned off.
2. If your system requires an SMS diskette, insert it into the diskette drive of the
client and turn on the machine. If you do not insert an SMS diskette at this
time, and one is required, you will be prompted to insert one later.
3. As icons begin to display from left to right on the bottom of your display, press
the F1 key for the Graphical SMS menu or the F4 key for an ASCII SMS
menu.
4. The SMS menu is displayed on your screen. You can do your hardware
testing or configuration as needed.
You can change the advisory password in the SMS menu so that only authorized
people can access the SMS utility. If you forget this password, the only way to
recover from this is to remove the on-board system battery.
3.4 Hardware device compatibility
RSPC and RS/6000 Platform Architecture (RPA) systems may support
attachment of devices using the following methods:
PCI
ISA
SCSI
Provided the device support software is installed, PCI and SCSI devices are
configured automatically whenever the Configuration Manager program (cfgmgr)
is run at system boot and when no conflict (for example, the same SCSI ID for
two SCSI devices) is found.
Note: If the last icon is displayed prior to pressing the F1 or F4 key, the
normal mode boot list is used instead of the System Management
Services diskette.
50 IBM ^ Certification Study Guide - pSeries AIX System Administration
Non-native ISA devices will have to be configured manually, and you may need to
change some of the device's predefined or customized attribute values especially
when configuring two or more ISA devices of the same type.
Even though you can have multiple adapters on one system, you may not always
be able to run different devices on the same adapter. There are various different
configurations according to the specification of your particular machine. For
example, if you have a SCSI Single-Ended (SE) Ultra Controller, only SE SCSI
devices can connect to it, not differential devices. Likewise, If you have a
100 Mbps Ethernet LAN, a 10 Mbps Ethernet card will not work.
3.4.1 Device configuration database
Device information is contained in a predefined database or a customized
database that makes up the Device Configuration Database managed by the
Object Data Manager (ODM).
The predefined database contains configuration data for all possible devices
configured to the system.
The customized database contains configuration data for all currently defined
and configured devices in the system.
The device information stored in the Device Configuration Database allows the
automatic configuration of microchannel devices on RISC System/6000 systems
and PCI devices on RSPC and RPA (non Micro Channel) systems whenever the
Configuration Manager (cfgmgr) program is run at system boot and run time.
As for non-native ISA devices, the information data contained in the predefined
part of the configuration database is not sufficient to perform automatic,
conflict-free, ISA device configuration. Thus, the user needs to manually
customize some values to be used by the ISA device (for example, interrupt level,
shared memory address, and so forth) when configuring the device for the first
time.
3.5 Using the lsattr command
After configuring all the devices in the system, you can use the lsattr command
to display information about the attributes of a given device or kind of device. If
you do not specify the device’s logical name (-l Name), you must use a
combination of one or all of the -c Class, -s Subclass, and -t Ty pe flags to
uniquely identify the predefined device. The general syntax of the lsattr
command is as follows:
lsattr { -D [ -O ] | -E [ -O ] | -F Format } -l Name [ -a Attribute ] ...
[ -f File ] [ -h ] [ -H ]
Chapter 3. Hardware assistance 51
lsattr { -D [ -O ] | -F Format } { [ -c Class ] [ -s Subclass ] [ -t Type ] }
[ -a Attribute ] ... [ -f File ] [ -h ] [ -H ]
lsattr -R { -l Name | [ -c Class ] [ -s Subclass ] [ -t Type ] } -a Attribute
[ -f File ] [ -h ] [ -H ]
The flags commonly used with the lsattr command are given in Table 3-5.
Table 3-5 lsattr command flags
Flag Description
-D Displays the attribute names, default values, descriptions, and
user-settable flag values for a specific device when not used with the
-O flag. The -D flag displays only the attribute name and default value
in colon format when used with the -O flag.
-E Displays the attribute names, current values, descriptions, and
user-settable flag values for a specific device when not used with the
-O flag. The -E flag only displays the attribute name and current value
in colon format when used with the -O flag. This flag cannot be used
with the -c, -D, -F, -R, -s, or -t flags.
-F Format Displays the output in a user-specified format.
-a Attribute Displays information for the specified attributes of a specific device or
kind of device.
-c Class Specifies a device class name. This flag cannot be used with the -E
or -l flags.
-f File Reads the needed flags from the File parameter.
-H Displays headers above the column output. To use the -H flag with
either the -O or the -R flags is meaningless; the -O or -R flag prevails.
-l Name Specifies the device logical name in the Customized Devices object
class whose attribute names or values are to be displayed.
-O Displays all attribute names separated by colons and, on the second
line, displays all the corresponding attribute values separated by
colons.
52 IBM ^ Certification Study Guide - pSeries AIX System Administration
When displaying the effective values of the attributes for a customized device, the
information is obtained from the Configuration database, not the device.
Generally, the database values reflect how the device is configured unless it is
reconfigured with the chdev command using the -P or -T flag. If this has occurred,
the information displayed by the lsattr command might not correctly indicate the
current device configuration until after the next system boot.
If you use the -D or -E flags, the output defaults to the values for the attribute's
name, value, description, and user-settable strings unless also used with the -O
flag. The -O flag displays the names of all attributes specified separated by
colons. On the next line, the -O flag displays all the corresponding attribute
values separated by colons. The -H flag can be used with either the -D, -E, or -F
flags to display headers above the column names. You can define the format of
the output with a user-specified format where the format parameter is a quoted
list of column names separated by non-alphanumeric characters or white space
using the -F Format flag.
-R Displays the legal values for an attribute name. The -R flag cannot be
used with the -D, -E, -F and -O flags, but can be used with any
combination of the -c, -s, and -t flags that uniquely identifies a device
from the Predefined Devices object class or with the -l flag. The -R
flag displays the list attribute values in a vertical column as follows:
Value1
Value2
.
.
ValueN
The -R flag displays the range attribute values as x...n(+i) where x is
the start of the range, n is the end of the range, and i is the increment.
-s Subclass Specifies a device subclass name. This flag can be used to restrict
the output to devices of a specified subclass. This flag cannot be used
with the -E or -l flags.
-t Type Specifies a device type name. This flag can be used to restrict the
output to devices of a specified class. This flag cannot be used with
the -E or -l flag.
Flag Description
Chapter 3. Hardware assistance 53
You can supply the flags either on the command line or from the specified file
parameter. The following are some examples of the usage of the lsattr
command.
To list the current attribute values for the tape device rmt0, use the lsattr
command as follows:
# lsattr -l rmt0 -E
mode yes Use DEVICE BUFFERS during writes True
block_size 1024 BLOCK size (0=variable length) True
extfm no Use EXTENDED file marks True
ret_error no RETURN error on tape change or reset True
To list the default attribute values for the tape device rmt0, use the lsattr
command as follows:
# lsattr -l rmt0 -D
mode yes Use DEVICE BUFFERS during writes True
block_size 1024 BLOCK size (0=variable length) True
extfm no Use EXTENDED file marks True
ret_error no RETURN error on tape change or reset True
To list the current value of the bus_intr_lvl attribute for the SCSI adapter scsi0,
use the lsattr command as follows:
# lsattr -l scsi0 -a bus_intr_lvl -E
bus_intr_lvl 14 Bus interrupt level False
To list the possible values of the login attribute for the TTY device tty0, use the
lsattr command as follows:
# lsattr -l tty0 -a login -R
enable
disable
share
delay
hold
To list the current value of the speed attribute for the serial port that tty0 is
connected to, use the lsattr command as follows:
# lsattr -El tty0 -a speed
speed 9600 BAUD rate True
Depending on your software configuration, you may see a different command
response than the previous one. Try the command with a different device and
attribute and experience how it behaves.
54 IBM ^ Certification Study Guide - pSeries AIX System Administration
3.6 Using SMIT with devices
The SMIT fast path smitty devices allows you to use the SMIT menu interface to
do the following:
Install or configure devices added after IPL.
Remove devices.
List existing devices.
Change or show the characteristics of devices.
Perform problem determination on devices.
3.7 The system error log
Once you have all the devices configured in your system and your system is in
production, you may encounter errors related to hardware during your normal
day-to-day operations. AIX provides the error logging facility for recording
hardware and software failures in an error log. This error log can be used for
information purposes or for fault detection and corrective actions.
The error logging process begins when an operating system module detects an
error. The error-detecting segment of code then sends error information to either
the errsave and errlast kernel service or the errlog application subroutine where
the information is, in turn, written to the /dev/error special file. This process then
adds a time stamp to the collected data. You can use the errpt command to
retrieve an error record from the error log.
3.7.1 Using the errdemon command
The errdemon process constantly checks the /dev/error file for new entries.
When new data matches an item in the Error Record Template Repository, the
daemon collects additional information from other system components.
The errdemon command is normally started automatically during system start-up,
however, if it has been terminated for any reason and you need to restart it,
enter:
/usr/lib/errdemon
Chapter 3. Hardware assistance 55
To determine the path to your system's error log file, run the following command:
# /usr/lib/errdemon -l
Error Log Attributes
--------------------------------------------
Log File /var/adm/ras/errlog
Log Size 1048576 bytes
Memory Buffer Size 8192 bytes
To change the maximum size of the error log file, enter:
/usr/lib/errdemon -s 2000000
To change the size of the error log device driver's internal buffer, enter:
/usr/lib/errdemon -B 16384
A message similar to the following is displayed:
0315-175 The error log memory buffer size you supplied will be rounded up to a
multiple of 4096 bytes.
3.7.2 Using the errpt command
To retrieve the entries in the error log, you can use the errpt command. The
errpt command generates an error report from entries in an error log. It includes
flags for selecting errors that match specific criteria. By using the default
condition, you can display error log entries in the reverse order in which they
occurred and were recorded.
The general syntax of the errpt command is as follows:
errpt [ -a ] [ -c ] [ -d ErrorClassList ] [ -e EndDate ] [ -g ] [ -i File ]
[ -j ErrorID [ ,ErrorID ] ] | [ -k ErrorID [ ,ErrorID ]] [ -J ErrorLabel
[ ,ErrorLabel ] ] | [ -K ErrorLabel [ ,ErrorLabel ] ] [ -l SequenceNumber ]
[ -m Machine ] [ -n Node ] [-s StartDate ] [ -F FlagList ]
[ -N ResourceNameList ] [ -R ResourceTypeList ] [ -S ResourceClassList ]
[ -T ErrorTypeList ] [ -y File ] [ -z File ]
Note: The errpt command does not perform error log analysis; for
analysis, use the diag command.
56 IBM ^ Certification Study Guide - pSeries AIX System Administration
Some of the most commonly used flags used with the errpt command are given
in Table 3-6.
Table 3-6 errpt command flags
The following sections show a few examples of using the errpt command.
Displaying errors in summary
To display a complete summary report of the errors that have been encountered
so far, on the command line, use the errpt command as follows:
# errpt
IDENTIFIER TIMESTAMP T C RESOURCE_NAME DESCRIPTION
2BFA76F6 1025181998 T S SYSPROC SYSTEM SHUTDOWN BY USER
9DBCFDEE 1025182198 T O errdemon ERROR LOGGING TURNED ON
2BFA76F6 1025175998 T S SYSPROC SYSTEM SHUTDOWN BY USER
9DBCFDEE 1025180298 T O errdemon ERROR LOGGING TURNED ON
2BFA76F6 1025174098 T S SYSPROC SYSTEM SHUTDOWN BY USER
9DBCFDEE 1025174398 T O errdemon ERROR LOGGING TURNED ON
.......... (Lines Removed)
2BFA76F6 1021134298 T S SYSPROC SYSTEM SHUTDOWN BY USER
9DBCFDEE 1021135098 T O errdemon ERROR LOGGING TURNED ON
2BFA76F6 1021120198 T S SYSPROC SYSTEM SHUTDOWN BY USER
Flag Description
-a Displays information about errors in the error log file in a
detailed format. If used in conjunction with the - t flag, all the
information from the template file is displayed.
-j ErrorID[,ErrorID] Includes only the error-log entries specified by the ErrorID
(error identifier) variable. The ErrorID variables can be
separated by commas (,) or enclosed in double quotation
marks ("") and separated by commas (,) or space characters.
When combined with the -t flag, entries are processed from
the error-template repository.
-s StartDate Specifies all records posted after the StartDate variable,
where the StartDate variable has the form mmddhhmmyy
(month, day, hour, minute, and year).
-t Processes the error-record template repository instead of the
error log. The -t flag can be used to view error-record
templates in report form.
-F FlagList Selects error-record templates according to the value of the
Alert, Log, or Report field of the template.
-J ErrorLabel Includes the error log entries specified by the ErrorLabel
variable.
Chapter 3. Hardware assistance 57
Displaying error details
To display a detailed report of all the errors encountered on the system, use the
errpt command as follows:
# errpt -a
-----------------------------------------------------------------------
LABEL: REBOOT_ID
IDENTIFIER: 2BFA76F6
Date/Time: Sun Oct 25 18:19:04
Sequence Number: 60
Machine Id: 006151474C00
Node Id: mynode
Class: S
Type: TEMP
Resource Name: SYSPROC
Description
SYSTEM SHUTDOWN BY USER
Probable Causes
SYSTEM SHUTDOWN
Detail Data
USER ID
0
0=SOFT IPL 1=HALT 2=TIME REBOOT
0
TIME TO REBOOT (FOR TIMED REBOOT ONLY)
.......... (Lines Removed)
-----------------------------------------------------------------------
LABEL: DISK_ERR3
IDENTIFIER: 35BFC499
Date/Time: Thu Oct 22 08:11:12
Sequence Number: 36
Machine Id: 006151474C00
Node Id: mynode
Class: H
Type: PERM
Resource Name: hdisk0
Resource Class: disk
Resource Type: scsd
Location: 04-B0-00-6,0
VPD:
Manufacturer................IBM
Machine Type and Model......DORS-32160 !#
FRU Number..................
ROS Level and ID............57413345
58 IBM ^ Certification Study Guide - pSeries AIX System Administration
Serial Number...............5U5W6388
EC Level....................85G3685
Part Number.................07H1132
Device Specific.(Z0)........000002028F00001A
Device Specific.(Z1)........39H2916
Device Specific.(Z2)........0933
Device Specific.(Z3)........1296
Device Specific.(Z4)........0001
Device Specific.(Z5)........16
Description
DISK OPERATION ERROR
Probable Causes
DASD DEVICE
STORAGE DEVICE CABLE
Failure Causes
DISK DRIVE
DISK DRIVE ELECTRONICS
STORAGE DEVICE CABLE
Recommended Actions
PERFORM PROBLEM DETERMINATION PROCEDURES
Detail Data
SENSE DATA
0A06 0000 2800 0088 0002 0000 0000 0200 0200 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0001 0001 2FC0
.......... (Lines Removed)
-----------------------------------------------------------------------
LABEL: ERRLOG_ON
IDENTIFIER: 9DBCFDEE
Date/Time: Fri Sep 18 14:56:55
Sequence Number: 14
Machine Id: 006151474C00
Node Id: mynode
Class: O
Type: TEMP
Resource Name: errdemon
Description
ERROR LOGGING TURNED ON
Probable Causes
Chapter 3. Hardware assistance 59
ERRDEMON STARTED AUTOMATICALLY
User Causes
/USR/LIB/ERRDEMON COMMAND
Recommended Actions
NONE
Displaying errors by time reference
If you suspect that the errors were encountered during the last day, you can
display a detailed report of all errors logged in the past 24 hours, where the string
equals the current month, day, hour, minute, and year, minus 24 hours. To do so,
use the errpt command as follows:
# date
Wed Aug 29 09:30:42 CDT 2001
# errpt -a -s 0828093001
---------------------------------------------------------------------------
LABEL: REBOOT_ID
IDENTIFIER: 2BFA76F6
Date/Time: Tue Aug 28 15:53:34
Sequence Number: 2
Machine Id: 003826424C00
Node Id: mynode
Class: S
Type: TEMP
Resource Name: SYSPROC
Description
SYSTEM SHUTDOWN BY USER
Probable Causes
SYSTEM SHUTDOWN
Detail Data
USER ID
0
0=SOFT IPL 1=HALT 2=TIME REBOOT
0
TIME TO REBOOT (FOR TIMED REBOOT ONLY)
0
---------------------------------------------------------------------------
LABEL: ERRLOG_ON
IDENTIFIER: 9DBCFDEE
Date/Time: Tue Aug 28 15:56:27
Sequence Number: 1
60 IBM ^ Certification Study Guide - pSeries AIX System Administration
Machine Id: 003826424C00
Node Id: mynode
Class: O
Type: TEMP
Resource Name: errdemon
Description
ERROR LOGGING TURNED ON
Probable Causes
ERRDEMON STARTED AUTOMATICALLY
User Causes
/USR/LIB/ERRDEMON COMMAND
Recommended Actions
NONE
3.7.3 Using the errlogger command
The errlogger command allows you to log operator messages to the system
error log. These messages can be up to 1024 bytes in length.
The use of the errlogger command and its output are shown in the following
example.
# errlogger Testing use of errlogger command
# errpt
IDENTIFIER TIMESTAMP T C RESOURCE_NAME DESCRIPTION
AA8AB241 0904103401 T O OPERATOR OPERATOR NOTIFICATION
1581762B 0831110701 T H cd0 DISK OPERATION ERROR
2BFA76F6 0828155301 T S SYSPROC SYSTEM SHUTDOWN BY USER
# errpt -a -j AA8AB241
---------------------------------------------------------------------------
LABEL: OPMSG
IDENTIFIER: AA8AB241
Date/Time: Tue Sep 4 10:34:17
Sequence Number: 6
Machine Id: 003826424C00
Node Id: mynode
Class: O
Type: TEMP
Resource Name: OPERATOR
Description
OPERATOR NOTIFICATION
User Causes
Chapter 3. Hardware assistance 61
ERRLOGGER COMMAND
Recommended Actions
REVIEW DETAILED DATA
Detail Data
MESSAGE FROM ERRLOGGER COMMAND
Testing use of errlogger command
#
3.7.4 Other error handling commands
In addition to the errpt command, the following commands can be used in
conjunction with the errpt command to find hardware errors and take corrective
measures for any problems reported by the error logging facility:
errclear Deletes entries from the error log.
errinstall Installs messages in the error logging message sets.
errupdate Updates the Error Record Template repository.
3.8 Diagnosing hardware problems
The diag command is the starting point to run a wide choice of tasks and service
aids that are used to perform hardware problem determination. The diag
command has a menu driven interface, but can also be directed to perform
specific tasks using command line flags.
Use the following steps to run diagnostics if you suspect a problem.
1. Run the diag command.
2. Press Enter to advance past the information screen.
3. Select Diagnostic Routines.
4. Select Problem Determination.
This instructs the diag command to test the system and analyze the error log.
Figure 3-7 on page 62 shows the results of running diagnostics on a system with
a problem.
62 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 3-7 diag screen showing a problem
Alternatively, you could use the diag -d sysplanar0 -v -e command to perform
the same diagnostics if you suspect a problem with the sysplanar0 device.
3.9 The system log
To log system messages, AIX uses syslogd. The syslogd daemon reads a
datagram socket and sends each message line to a destination described by the
/etc/syslog.conf configuration file. The syslogd daemon reads the configuration
file when it is activated and when it receives a hang-up signal.
The syslogd daemon creates the /etc/syslog.pid file. This file contains a single
line with the command process ID of the syslogd daemon. It is used to end or
reconfigure the syslogd daemon.
A terminate signal sent to the syslogd daemon ends the daemon. The syslogd
daemon logs the end-signal information and terminates immediately.
Each message is one line. A message can contain a priority code marked by a
digit enclosed in angle braces (< >) at the beginning of the line. Messages longer
than 900 bytes may be truncated.
Chapter 3. Hardware assistance 63
The /usr/include/sys/syslog.h include file defines the facility and priority codes
used by the configuration file. Locally written applications use the definitions
contained in the syslog.h file to log messages using the syslogd daemon.
The general syntax of the syslogd command is as follows:
syslogd [ -d ] [ -s ] [ -f ConfigurationFile ] [ -m MarkInterval ] [-r]
The flags commonly used when starting syslogd are provided in Table 3-7.
Table 3-7 syslogd daemon flags
The syslogd daemon uses a configuration file to determine where to send a
system message depending on the message's priority level and the facility that
generated it. By default, syslogd reads the default configuration file
/etc/syslog.conf, but if you specify the -f flag, you can specify an alternate
configuration file.
3.9.1 The syslogd configuration file
The /etc/syslog.conf file controls the behavior of the syslogd daemon. For
example, syslogd uses /etc/syslog.conf file to determine where to send the error
messages or how to react to different system events. The following is a part of
the default /etc/syslog.conf file.
/etc/syslog.conf - control output of syslogd
#
# Each line must consist of two parts:-
#
# 1) A selector to determine the message priorities to which the
# line applies
# 2) An action.
Flag Description
-d Turns on debugging.
-f Config File Specifies an alternate configuration file.
-m MarkInterval Specifies the number of minutes between the mark command
messages. If you do not use this flag, the mark command sends a
message with LOG_INFO priority every 20 minutes. This facility is
not enabled by a selector field containing an * (asterisk), which
selects all other facilities.
-s Specifies to forward a shortened message to another system (if it is
configured to do so) for all the forwarding syslogd messages
generated on the local system.
-r Suppresses logging of messages received from remote hosts.
64 IBM ^ Certification Study Guide - pSeries AIX System Administration
#
# The two fields must be separated by one or more tabs or spaces.
#
# format:
#
# <msg_src_list> <destination>
#
# where <msg_src_list> is a semicolon separated list of <facility>.<priority>
# where:
#
# <facility> is:
# * - all (except mark)
# mark - time marks
# kern,user,mail,daemon, auth,... (see syslogd(AIX Commands Reference))
#
# <priority> is one of (from high to low):
# emerg/panic,alert,crit,err(or),warn(ing),notice,info,debug
# (meaning all messages of this priority or higher)
#
# <destination> is:
# /filename - log to this file
# username[,username2...] - write to user(s)
# @hostname - send to syslogd on this machine
# * - send to all logged in users
#
# example:
# "mail messages, at debug or higher, go to Log file. File must exist."
# "all facilities, at debug and higher, go to console"
# "all facilities, at crit or higher, go to all users"
# mail.debug /usr/spool/mqueue/syslog
# *.debug /dev/console
# *.crit *
In addition to the /etc/syslog.conf file that contains the settings for the syslogd
daemon, the /etc/syslog.pid file contains the process ID of the running syslogd
daemon.
3.9.2 The format of the configuration file
This section describes what the format of the /etc/syslog.conf file is and how you
can interpret the different entries in this file. Lines in the configuration file for the
syslogd daemon contain a selector field and an action field separated by one or
more tabs.
Chapter 3. Hardware assistance 65
The selector field names a facility and a priority level. Separate the facility names
with a comma (,) separate the facility and priority-level portions of the selector
field with a period (.), and separate multiple entries in the same selector field with
a semicolon (;). To select all facilities, use an asterisk (*).
The action field identifies a destination (file, host, or user) to receive the
messages. If routed to a remote host, the remote system will handle the
message as indicated in its own configuration file. To display messages on a
user's terminal, the destination field must contain the name of a valid, logged-in
system user.
Facilities
Table 3-8 lists some of the facilities used in the /etc/syslog.conf file. You can use
these system facility names in the selector field.
Table 3-8 Facilities used in the /etc/syslog.conf file
Facility Description
kern Kernel
user User level
mail Mail subsystem
daemon System daemons
auth Security or authorization
syslog syslogd daemon
lpr Line-printer subsystem
news News subsystem
uucp uucp subsystem
* All facilities
66 IBM ^ Certification Study Guide - pSeries AIX System Administration
Priority levels
Table 3-9 lists the priority levels used in the /etc/syslog.conf file. You can use the
message priority levels in the selector field. Messages of the specified priority
level and all levels above it are sent as directed.
Table 3-9 Priority levels for the /etc/syslog.conf file
Priority Level Description
emerg Specifies emergency messages (LOG_EMERG). These messages
are not distributed to all users. LOG_EMERG priority messages can
be logged into a separate file for reviewing.
alert Specifies important messages (LOG_ALERT), such as a serious
hardware error. These messages are distributed to all users.
crit Specifies critical messages not classified as errors (LOG_CRIT),
such as improper login attempts. LOG_CRIT and higher-priority
messages are sent to the system console.
err Specifies messages that represent error conditions (LOG_ERR),
such as an unsuccessful disk write.
warning Specifies messages for abnormal, but recoverable, conditions
(LOG_WARNING).
notice Specifies important informational messages (LOG_NOTICE).
Messages without a priority designation are mapped into this priority.
These are more important than informational messages, but not
warnings.
info Specifies informational messages (LOG_INFO). These messages
can be discarded but are useful in analyzing the system.
debug Specifies debugging messages (LOG_DEBUG). These messages
may be discarded.
none Excludes the selected facility. This priority level is useful only if
preceded by an entry with an * (asterisk) in the same selector field.
Chapter 3. Hardware assistance 67
Destinations
Table 3-10 lists a few of the destinations that are used in the /etc/syslog.conf file.
You can use these message destinations in the action field.
Table 3-10 Destination description for the /etc/syslog.conf file
3.9.3 Using the system log
To customize the /etc/syslog.conf file so that your required conditions are met,
the system log should be updated by editing the /etc/syslog.conf file. After you
have edited and added your lines to the /etc/syslog.conf file, you need to restart
the syslogd daemon. You can do this by running the following commands:
1. Check to see what the syslogd daemon process ID is. In this case, it is 5426.
# ps -ef | grep syslogd
root 5426 4168 0 Nov 01 - 0:00 /usr/sbin/syslogd
root 24938 25854 2 12:04:03 pts/6 0:00 grep syslog
2. Use the stopsrc command to stop the syslogd daemon as follows:
# stopsrc -s syslogd
0513-044 The stop of the syslogd Subsystem was completed successfully.
3. Check if the syslogd daemon has been stopped successfully.
# ps -ef | grep syslogd
root 26112 25854 2 12:04:16 pts/6 0:00 grep syslog
4. Restart the syslogd daemon.
# startsrc -s syslogd
0513-059 The syslogd Subsystem has been started. Subsystem PID is 13494.
The following are a few examples on the /etc/syslog.conf file usage.
To log all mail facility messages at the debug level or above to the file
/tmp/mailsyslog, enter:
mail.debug /tmp/mailsyslog
Where:
–
mail is the Facility as per Table 3-8 on page 65.
Destination Description
File Name Full path name of a file opened in append mode.
@Host Host name, preceded by @ (at sign).
User[, User][...] User names.
* All users.
68 IBM ^ Certification Study Guide - pSeries AIX System Administration
– debug is the Priority Level as per Table 3-9 on page 66.
–
/tmp/mailsyslog is the Destination as per Table 3-10 on page 67.
To send all system messages except those from the mail facility to a host
named rigil, enter:
*.debug;mail.none @rigil
Where:
–
* and mail are the Facilities as per Table 3-8 on page 65.
–
debug and none are the Priority Levels as per Table 3-9 on page 66.
–
@rigil is the Destination as per Table 3-10 on page 67.
To send messages at the emerg priority level from all facilities and messages
at the crit priority level and above from the mail and daemon facilities to users
nick and jam, enter:
*.emerg;mail,daemon.crit nick, jam
Where:
–
*, mail and daemon are the Facilities as per Table 3-8 on page 65.
–
emerg and crit are the Priority Levels as per Table 3-9 on page 66.
–
nick and jam are the Destinations as per Table 3-10 on page 67.
To send all mail facility messages to all users' terminal screens, enter:
mail.debug *
Where:
–
mail is the Facility as per Table 3-8 on page 65.
–
debug is the Priority Level as per Table 3-9 on page 66.
–
* is the Destination as per Table 3-10 on page 67.
3.10 Setting up an ASCII terminal
The 3151 display can connect directly, or through a modem, to an AIX system.
The connection to the AIX system can be made to one of the native serial ports,
as shown in Figure 3-8, or to an asynchronous adapter, as shown in Figure 3-9
on page 69. Additionally, a printer can be connected to the 3151 display and is
supported by AIX as Terminal Attached Printing, as displayed in Figure 3-8 on
page 69.
Chapter 3. Hardware assistance 69
Figure 3-8 Attaching a serial terminal to an RS/6000 system
Figure 3-9 Terminal connection to direct-attached asynchronous adapter
To add a TTY, use the following procedure:
1. Issue smitty tty and select Add a TTY or issue smitty maktty.
2. The system will ask you for the TTY type and the parent adapter. Select the
correct values from the list and press Enter.
A screen similar to Figure 3-10 on page 70 will be shown:
70 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 3-10 Adding a tty
3. Select the port number you want this TTY to be added to in the PORT number
field. For RANs, follow the location code rules to select the appropriate port
number.
4. Change the TERMINAL Type field to the type of terminal you are using. This
field is very important since you might not be able to use all the keys on your
terminal if this field is set incorrectly. The TERM environment variable stores
this setting. You can change the terminal emulation setting by using your
TERM environment variable and using the export command to store the
terminal emulation you want to use. For example, to use ibm3151 terminal
emulation, use the command:
TERM=ibm3151; export TERM
5. Set the line speed and the kind of communication (1/8/N or 1/7/E) for your
terminal and press Enter.
This will create a device special file in the /dev directory and add an entry to
the /etc/inittab file to run the getty process on your terminal so that your
terminal is available at system startup. It also adds another entry to the
customized ODM (CuDv) database for the terminal you have just added.
You can also add a TTY directly on the command line. To add an ibm3151 RS232
terminal using adapter sa0, and port s1, with login enabled use the following
command:
mkdev -c tty -t tty -s rs232 -p sa0 -w s1 -a login=enable -a term=ibm3151
Chapter 3. Hardware assistance 71
You can remove a terminal by using the command:
rmdev -l tty_name -d
Where tty_name can be determined by using the command tty or by listing
all the TTYs and then selecting the tty you want to remove.
On the ASCII terminal, set the communications options as follows:
Line Speed (baud rate) = 9600
Word Length (bits per character) = 8
Parity = no (none)
Number of Stop Bits = 1
Interface = RS-232C (or RS-422A)
Line Control = IPRTS
Set the keyboard and display options as follows:
Screen = normal
Row and Column = 24x80
Scroll = jump
Auto LF (line feed) = off
Line Wrap = on
Forcing Insert = line (or both)
Tab = field
Operating Mode = echo
Turnaround Character = CR
Enter = return
Return = new line
New Line = CR
Send = page
Insert Character = space
Note: If your terminal is an IBM 3151, 3161, or 3164, press the Ctrl+Setup
keys to display the Setup Menu and follow the on-screen instructions to set
these fields.
If you are using some other ASCII terminal, refer to the appropriate
documents for information about how to set these fields.
72 IBM ^ Certification Study Guide - pSeries AIX System Administration
3.11 Quiz
The following are questions created by the authors to further test your
understanding of the topics.
1. The marketing group within the Widget Company plans to implement a new
database to house their demographic data. The administrator has requested
a tape drive and an additional disk to support the installation of this new
database. The IBM hardware engineer has connected the new equipment,
and the machine has been rebooted. Which of the following commands
should be used to verify the tape device is installed correctly?
A. lspv
B. lsdev
C. lstape
D. lsdisk
2. The marketing group within the Widget Company plans to implement a new
database, as in question one. The new tape drive appears to be installed and
functioning correctly. However, while attempting to perform a mksysb utilizing
the new drive, it fails. What would be the first recommended action to take to
determine the cause of the failure?
A. Replace the tape drive.
B. Run cfgmgr to reconfigure the tape device.
C. Check the error log for tape drive errors.
D. Use SMIT to change the compression attribute on the tape device.
3. A system administrator has just set up a new machine with two external hard
disks in a SCSI chain. One is a 2.2 GB SE (single ended) disk, and the other
is a 4.5 GB differential disk. The system administrator reboots the machine
and notices that only the SE disk is available. Which of the following is the
most likely cause?
A. The SE disk is most likely experiencing hardware problems.
B. There is most likely a SCSI conflict between the two drives.
C. The SE and differential drives are on the same chain.
D. The differential disk is most likely experiencing hardware problems.
Chapter 3. Hardware assistance 73
4. Which of the following commands can be used to determine the serial port
settings?
A. lscfg -vl ttyXX
B. ls -l /dev/ttyXX
C. lsattr -El ttyXX
D. lsdev -C |grep ttyXX
5. A machine has a bootlist that is set for network booting. In attempting to
access SMS menus to change the bootlist to the local disk, it is discovered
that someone has set an SMS supervisory password, and the password is not
recorded. Which of the following actions will allow the system administrator to
gain access to the SMS menus?
A. Boot from AIX installation media, then reinstall SMS.
B. Boot from AIX installation media, then reset the supervisory password.
C. Call IBM and ask for the over-ride password based on the serial number.
D. Remove the battery from the system for at least one minute. Replace the
battery and then reboot.
3.11.1 Answers
The following answers are for the quiz questions.
1. B
2. C
3. C
4. C
5. D
3.12 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Check the error log. Are there any problems you should worry about?
2. Check the system log. Determine what information is in the file and add
additional information that you want reported on.
3. Configure a new device. Use the cfgmgr command to configure the device.
74 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 75
Chapter 4. System and software
installation
This chapter describes the installation process, the common commands that are
used with the installation process, and the different methods available to you for
installing software onto a system. It covers Base Operating System (BOS)
installation options, installation of the optional software, and the application of
updates to bring your system to the latest maintenance level.
4
76 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 4-1 shows a flow chart of the steps for installing a system.
Figure 4-1 Flow chart for AIX 5L Version 5.1 system installation
4.1 Base Operating System installation
To install the Base Operating System, you should first boot the system into
maintenance mode. The Welcome to Base Operating System Installation and
Maintenance screen is displayed, similar to the one in Figure 4-2 on page 77.
78 IBM ^ Certification Study Guide - pSeries AIX System Administration
Select 3 on this screen, and you will be shown a screen similar to Figure 4-4.
Figure 4-4 Advanced Options menu
In the Installation and Settings screen, you can set the method of installation, the
primary language environment settings, and modify advanced options. There are
three ways in which you can install AIX on your system. These methods are as
follows:
New and Complete Overwrite Installation
Migration Installation
Preservation Installation
4.1.1 New and Complete Overwrite installation
Generally, the New and Complete Overwrite method is used when:
You have a new machine. In this case, the hard disk or disks on which you are
installing the BOS are empty. This is the only possible installation method for
a new machine.
You want to install onto a hard disk that contains an existing root volume
group that you wish to completely overwrite. For example, this might occur if
your root volume group has become corrupted.
You want to reassign your hard disks, that is, to make your rootvg smaller and
assign less disk space to it.
Chapter 4. System and software installation 79
4.1.2 Migration installation
Use this installation method to upgrade AIX Version 3.2, AIX Version 4.1,
AIX Version 4.2, or AIX Version 4.3 to AIX 5L Version 5.1 while preserving the
existing root volume group. With the exception of /tmp, this method preserves all
file systems, including the root volume group, logical volumes, and system
configuration files. Migration is the default installation method for AIX Version 3.2,
AIX Version 4.1, and AIX Version 4.2 machines.
In most cases, the user configuration files from the previous version of a product
are saved when the new version is installed during a Migration installation.
4.1.3 Preservation installation
Use this installation method when a version of the BOS is installed on your
system, and you want to preserve the user data in the root volume group.
However, this method overwrites the /usr, /tmp, /var, and / (root) file systems by
default; so, any user data in these directories is lost. These file systems are
removed and recreated; so, any other LPPs or filesets that you installed on the
system will also be lost. System configuration must be done after doing a
Preservation installation.
The /etc/preserve.list file contains a list of system files to be copied and saved
during a preservation BOS installation. The /etc/filesystems file is listed by
default. You can add the full path names of any additional files that you want to
save during the Preservation installation to the preserve.list file. For example, you
can alter the /etc/preserve.list file to tell your installation process that you want to
preserve your /var file system.
For detailed information on installing the BOS, refer to the AIX Installation Guide.
Note: The New and Complete Overwrite installation overwrites all data on
the selected destination disk. This means that, after the installation is
complete, you will have to manually configure your system using the
Configuration Assistant application, SMIT, or the command line. If you want
to preserve your system configuration, and you do not need to completely
overwrite your root volume group, do not use the New and Complete
Overwrite option.
80 IBM ^ Certification Study Guide - pSeries AIX System Administration
4.2 Advanced Options installation
In the AIX 5L Version 5.1 Advanced Options screen, you can modify more
settings for system operations parameters. There are three options you can
modify:
Installation Package Set or Desktop
Enable Trusted Computing Base
Enable 64-bit Kernel and JFS2
4.2.1 Installation Package Set or Desktop
The Installation Package Set or Desktop screen allows you to configure the type
of interface that the system will use at startup. The Installation Package Set is the
default and is the only selection for ASCII consoles.
The Desktop selection is for graphical systems. This will allow you to choose the
type of graphical interface to use with the system. The types of graphical
interfaces are:
CDE
KDE
GNOME
NONE
If you do not choose a desktop by selecting NONE, a minimal configuration is
installed including X11, Java, perl, SMIT, and the Web-based System Manager. If
you choose CDE, GNOME, or KDE, the desktop and documentation service
libraries are also installed. If you choose GNOME or KDE, the interface prompts
you for the Toolbox for Linux Applications CD-ROM. If this CD-ROM is not
available, you can type q to continue the installation without it.
For detailed information on the Installation Package Set or Desktop settings, refer
to the AIX 5L Version 5.1 Installation Guide, SC23-4374.
4.2.2 Enable Trusted Computing Base (TCB)
The Trusted Computing Base provides an extra level of security and ensures that
whatever you are trying to run is actually run. If you set this attribute to YES, the
install process installs the bos.rte.security fileset and you can configure TCB. It is
important to note that you can enable TCB only at this time. If you decide not to
install TCB now, you will have to reinstall the operating system to enable TCB at
a later stage. TCB can be removed by removing the bos.rte.security fileset from
the system.
Chapter 4. System and software installation 81
4.2.3 Enable 64-bit Kernel and JFS2
AIX 5L Version 5.1 allows you to install a 64-bit kernel as well as the previously
available 32-bit kernel during installation. If your system has 64-bit processors,
the 64-bit kernel is automatically loaded with the base operating system.
However, the 64-bit kernel is only enabled if you set the Enable 64-bit Kernel and
JFS2 option to yes during the initial AIX installation.
You can also install this kernel later by installing the bos.mp64 fileset.
The bootinfo -y command will identify the type of system hardware you have,
either 32-bit or 64-bit. If the command returns a 32, you cannot use the 64-bit
kernel.
JFS2 is an enhanced and updated version of the Journaled File System (JFS)
from AIX Version 4.3 and previous releases. JFS2 allows for features such as file
sizes of 1 terabyte (TB) and architectural maximum file system sizes of
4 petabytes (PB) in size. JFS2 also allows you to create Enhanced Journaled
File Systems on the system.
If you are using the New and Complete Overwrite installation, the installation will
create JFS2 file systems in the rootvg. If your system is not 64-bit enabled, this
option will not be displayed. If your system is 64-bit enabled and you do a
migration installation, this option will be enabled, but it will not convert the
existing file systems to JFS2.
Once you have installed the BOS, configured the Advanced Options, and the
system has booted from the hard disk, the system will take you to the
Configuration Assistant menu.
4.3 Configuration Assistant
After the installation is completed and the system reboots, the Configuration
Assistant program, /usr/sbin/install_assist, is automatically started. In
previous versions of AIX, the Configuration Assistant was known as the
Installation Assistant or the Configuration Assistant Taskguide.
The Configuration Assistant allows you to set up basic system configurations, as
shown in Figure 4-5 on page 82.
82 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 4-5 Configuration Assistant menu
On a system installed from an ASCII terminal, a similar list will appear in
character format.
After completing these tasks using the Configuration Assistant, you should
disable the automatic restart of the Configuration Assistant upon reboot.
Otherwise, it will appear on the console every time the system is rebooted. To
disable the automatic restart, do the following steps:
Select Exit the Configuraton Assistant.
Click Next.
Select Finish now, and do not start Configuration Assistant when restarting
the operating system.
If you need to call the Configuration Assistant again, run
/usr/sbin/install_assist, or use the SMIT fast path smitty assist.
4.4 Understanding maintenance levels
Once you have installed the base operating system, you can determine the
maintenance level with the oslevel command.
Chapter 4. System and software installation 83
The general syntax of the oslevel command is as follows:
oslevel [ -l Level | -g | -q ]
A brief description of the oslevel command flags is given in Table 4-1.
Table 4-1 Command flags for oslevel
To see the current maintenance level of your system, use the oslevel command
as follows:
# oslevel
4.3.2.0
The product name and level number identify a software product. The level of a
software product in AIX Version 3.2 and later is defined as vv.rr.mmmm.ffff,
where:
vv Is a numeric field of one to two digits that identifies the version number.
rr Is a numeric field of one to two digits that identifies the release number.
mmmm Is a numeric field of one to four digits that identifies the modification
level.
ffff Is a numeric field of one to four digits that identifies the fix level.
For example, bos.net.tcp.client 4.3.2.0 is a fileset, and bos.net.tcp.client 4.3.2.1 is
an update to that fileset. If there is another fileset update, bos.net.tcp.client
4.3.2.2 is generated. This update will contain all the fixes that were in the
bos.net.tcp.client 4.3.2.1. If a cumulative AIX update is generated, the
modification level of the fileset will increment resulting in bos.net.tcp.client
4.3.3.0, which would contain all previous fixes.
After an update, if your system is not showing the new maintenance level, use
the -l flag with the oslevel command to determine what filesets have not been
upgraded to match the new BOS level. In Figure 4-6 on page 84, the system is at
4.3.0.0, but there are some filesets that are not at the current maintenance level.
Flag Description
-l Level Lists filesets at levels earlier than the maintenance levels specified by
the Level parameter.
-g Lists filesets at levels later than the current maintenance level.
-q Lists names of known maintenance levels that can be specified using
the -l flag.
84 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 4-6 Sample oslevel -l output
The oslevel command can also be used to verify that a system has been
successfully migrated from a lower version of AIX to a higher version. For
example, on a system that has just been migrated to AIX 5L Version 5.1 from AIX
Version 4.3.3, the oslevel command would show the following:
# oslevel
5.1.0.0
# oslevel -l 5.1.0.0
#
4.5 Software packaging
Software products include those shipped with AIX and those purchased
separately. Each software product can contain separately installable parts. The
following explains how software products are organized.
4.5.1 Filesets
A fileset is the smallest installable base unit for the AIX operating system. A
fileset includes all files that constitute a complete product, such as bos.net.uucp,
or a separately installable part of a product, such as bos.net.nfs.client.
Chapter 4. System and software installation 85
4.5.2 Packages
A package is a group of separately installable filesets that provide a set of related
functions. For example, bos.net is a package.
4.5.3 Licensed Program Products
A Licensed Program Product (LPP) is a complete software product including all
packages associated with that licensed program. For example, the BOS is a
licensed program.
4.5.4 Bundles
A bundle is a list of software that can contain filesets, packages, and LPPs that
are suited for a particular use, such as providing personal productivity software
or software for a client machine in a network environment. Bundles that are used
by default for the system are stored in /usr/sys/inst.data/sys_bundles. Bundles
that are user-created are stored in /usr/sys/inst.data/user_bundles. The system
defined bundles in AIX 5L Version 5.1 are:
App-Dev
CDE
GNOME
KDE
Media-Defined
Netscape
devices
wsm_remote
4.5.5 PTFs and APARs
PTF is an acronym for Program Temporary Fix. A PTF is an updated fileset or a
fileset that fixes a previous system problem. PTFs are installed in the same way
as regular filesets by the use of the installp command, described in
Section 4.6.1, “The installp command” on page 86.
APAR is an acronym for Authorized Program Analysis Report. An APAR is an
emergency fix, or e-fix, to a unique problem on the system. APARs will eventually
become PTFs after testing and verification. APARs are applied to the system
through the use of the instfix command, described in Section 4.7.3, “Displaying
and updating installed software to the latest level” on page 100.
86 IBM ^ Certification Study Guide - pSeries AIX System Administration
4.6 Installing optional software and service updates
Once you have installed the base operating system, only a limited number of
filesets are installed on your system. For a complete listing of the software that is
installed during the BOS installation, consult your AIX installation guides.
To install additional software, you can use SMIT or the command line. If you
decide to use the command line to install your software, you should be familiar
with the installp command.
4.6.1 The installp command
The installp command is used to install and update software. The installp
command has a large number of flags. In the following sections, only the most
important flags are shown with each command. The installp command is also
used by all the SMIT scripts to install software.
The flags commonly used with the installp command are listed in Table 4-2:
Table 4-2 Command flags for installp
Flag Description
-a Applies one or more software products or updates. This is the default
action. This flag can be used with the -c flag to apply and commit a
software product update during installation.
-B Indicates that the requested action should be limited to software
updates.
-C Cleans up after an interrupted installation and attempts to remove all
incomplete pieces of the previous installation.
-c Commits applied updates to the system.
-d Device Specifies on what device the installation media can be found.
-F Forces the installation of a software product even if there exists a
previously installed version of the software product that is the same
version as or newer than the one being installed.
-f ListFile Reads the names of the software products from ListFile. If ListFile is
a - (dash), it reads the list of names from the standard input. Output
from the installp -l command is suitable for input to this flag.
-g When used to install or commit, this flag automatically installs or
commits, respectively, any software products or updates that are
requisites of the specified software product. When used to remove or
reject software, this flag automatically removes or rejects dependents
of the specified software.
Chapter 4. System and software installation 87
Installing software
Software can be installed in one of two states: applied or committed. The applied
state places software on the system and retains the previous version of the
software. When an update is in the applied state, the previous version is stored in
the /usr/lpp/PackageName directory. This is useful for deploying or testing new
software, where it may be necessary to go back to the previous version of the
software in case of errors.
The committed state places software on the system and removes all previous
levels of the software from the /usr/lpp/PackageName directory. If committed
software needs to be removed, you cannot go back to the previous version
without a complete reinstall of the previous version software. We recommend you
install new software in the applied state, rather than the committed state, until the
new software has been thoroughly tested.
-L Displays the contents of the media by looking at the table of contents
(.toc) and displaying the information in colon-separated output. This
flag is used by SMIT to list the content of the media.
-l (lowercase
L)
Lists all the software products and their separately installable options
contained on the installation media to the standard output. No
installation occurs.
-N Overrides saving of existing files that are replaced when installing or
updating. This flag is valid only with the -ac flags.
-p Performs a preview of an action by running all preinstallation checks
for the specified action. This flag is only valid with apply, commit,
reject, and remove (-a, -c, -r, and -u) flags.
-r Rejects all software updates that are currently applied but not
committed.
-u Removes the specified software product and any of its installed
updates from the system. Removal of any bos.rte fileset is never
permitted.
-V Number Specifies the verbose option that can provide up to four levels of detail
for preinstallation output, including SUCCESSES, WARNINGS, and
FAILURES.
-v Verifies that all installed files in the fileset have the correct checksum
value after installation. Can be used with the -a and -ac flags to
confirm a successful installation. If any errors are reported by this
flag, it may be necessary to reinstall the software.
-X Attempts to expand any file systems where there is insufficient space
to do the installation.
Flag Description
88 IBM ^ Certification Study Guide - pSeries AIX System Administration
To install software in an applied state, the command syntax for the installp
command is:
installp -a [ -eLogFile ] [ -V Number ] [ -dDevice ] [ -b ] [ -S ] [ -B ]
[ -D ] [ -I ] [ -p ] [ -Q ] [ -q ] [ -v ] [ -X ] [ -F | -g ] [ -O { [ r ] [ s ]
[ u ] } ] [ -tSaveDirectory ] [ -w ] [ -zBlockSize ] { FilesetName [ Level ]...
| -f ListFile | all }
To install software in a committed state, the command syntax is:
installp -ac [ -N ] [ -eLogFile ] [ -V Number ] [ -dDevice ] [ -b ] [ -S ]
[ -B ] [ -D ] [ -I ] [ -p ] [ -Q ] [ -q ] [ -v ] [ -X ] [ -F | -g ]
[ -O { [ r ] [ s ] [ u ] } ] [ -tSaveDirectory ] [ -w ]
[ -zBlockSize ] { FilesetName [ Level ]... | -f ListFile | all }
For example, to install all filesets within the bos.net software package in
/usr/sys/inst.images directory in the applied state, with a checksum check, enter:
installp -avX -d/usr/sys/inst.images bos.net
To preview an install of all filesets within the bos.net software package in
/usr/sys/inst.images directory in the committed state and to check for disk space
requirements, enter:
installp -acpX -d/usr/sys/inst.images bos.net
Under the RESOURCES section in the output, you will see something similar to:
RESOURCES
---------
Estimated system resource requirements for filesets being installed:
(All sizes are in 512-byte blocks)
Filesystem Needed Space Free Space
/ 1150 17624
/usr 54183 48016
/var 8 22424
/tmp 300 63280
----- -------- ------
TOTAL: 55641 151344
NOTE: "Needed Space" values are calculated from data available prior
to installation. These are the estimated resources required for the
entire operation. Further resource checks will be made during
installation to verify that these initial estimates are sufficient.
As shown, the /usr file system does not have enough free space for the
installation, and the installation would fail.
Chapter 4. System and software installation 89
A record of the installp output can be found in /var/adm/sw/installp.summary.
The following is a sample of the file:
# cat /var/adm/sw/installp.summary
0:bos.net.ppp:5:U:5.1.0.0:
0:bos.net.ipsec.rte:5:U:5.1.0.0:
0:bos.net.ppp:5:R:5.1.0.0:
0:bos.net.ipsec.rte:5:R:5.1.0.0:
Committing applied updates
The command syntax for the installp command to commit applied updates is:
installp -c [ -eLogFile ] [ -VNumber ] [ -b ] [ -g ] [ -p ] [ -v ] [ -X ]
[ -O { [ r ] [ s ] [ u ] } ] [ -w ] { FilesetName [ Level ]... | -f ListFile |
all }
For example, to commit all updates, enter:
# installp -cgX all
Running this command will commit all the updates and will remove the filesets for
the previous version.
Rejecting applied updates
The command syntax for the installp command to reject the updates that are in
the applied state is:
installp -r [ -eLogFile ] [ -VNumber ] [ -b ] [ -g ] [ -p ] [ -v ] [ -X ]
[ -O { [ r ] [ s ] [ u ] } ] [ -w ] { FilesetName [ Level ]... | -f ListFile }
For example, to reject all applied updates listed in the file ./reject.list, enter:
# installp -rBfX ./reject.list
Running this command will remove all the uncommitted updates listed in
./reject.list and bring the system back to the previous maintenance level.
Note: If you try to run two installp commands at a time from the same
installation medium, it will fail with an error similar to:
0503-430 installp: Either there is an installp process currently running
or there is a previously failed installation. Wait for the process to
complete or run installp -C to cleanup a failed installation.
90 IBM ^ Certification Study Guide - pSeries AIX System Administration
Removing Installed software
If you want to remove an installed product, that is, remove all files that belong to
that software from the system, use the installp command; the command syntax
is:
installp -u [ -eLogFile ] [ -VNumber ] [ -b ] [ -g ] [ -p ] [ -v ] [ -X ]
[ -O { [ r ] [ s ] [ u ] } ] [ -w ] { FilesetName [ Level ]... | -f ListFile }
For example, to preview a remove of bos.net.ipsec.rte and its dependents, with a
verbose display of all successes, warnings, and failures, enter:
# installp -ugp -V2 bos.net.ipsec.rte
Running this command will give you a list of files that will be removed, but will not
actually remove them.
Cleaning up after failed installations
If an installation fails, installp will not be able to install the same software until
you have removed those files that succeeded in installing prior to the failure. You
can use the installp command as follows:
installp -C [ -b ] [ -eLogFile ]
For example, if all the prerequisites in an installation are not met, the installp
command might fail. You will not be able to reinstall the product until you have
done a cleanup. to do this, enter:
# installp -C
This will remove all the files installed in the failed installation.
Listing all installable software on media
To see what software is available on a particular media, the command syntax for
the installp command is:
installp { -l | -L } [ -eLogFile ] [ -d Device ] [ -B ] [ -I ] [ -q ]
[ -zBlockSize ] [ -O { [ s ] [ u ] } ]
For example, to list the software that is on your CD-ROM, enter:
# installp -L -d /dev/cd0
4.6.2 Using SMIT for software maintenance
Software installation, uninstallation, and maintenance tasks can also be
performed through the SMIT menus. SMIT uses the installp command to
perform these tasks.
Chapter 4. System and software installation 91
Software installation
To install software products:
1. Use the SMIT fast path smitty install_latest
A screen similar to Figure 4-7 is shown.
Figure 4-7 Install and Update from LATEST Available Software menu
2. Enter the device name for installation in the INPUT device/directory for
software field. A screen similar to Figure 4-8 on page 92 is shown.
Note: SMIT stores a record of software installation, removal, and maintenance
tasks in /var/adm/sw/installp.log like the installp command, but SMIT also
stores a more detailed record in $HOME/smit.log.
92 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 4-8 Install and Update from LATEST Available Software menu - more
3. In the SOFTWARE to install field, either enter the name, if you know what you
have to install, or press F4 to get a list of all the available software. Press
Enter once you have selected the products you want to install.
4. It is recommended that you first verify that the software you are trying to install
meets all the prerequisite and co-requisite requirements. It is a good practice
to set the PREVIEW only? (install operation will NOT occur) field to YES. This
will give you a detailed listing of whether your installation will be successful or
not.
5. It is recommended that you accept the default values for the
AUTOMATICALLY install requisite software (default YES) and EXTEND file
systems (default YES) fields if space is needed. Your installation might fail if
you tell installp not to extend the file system. If it runs out of space, an error
similar to the one shown below can be encountered:
0503-008 installp: There is not enough free disk space in file system
/usr (506935 more 512-byte blocks are required). An attempt to extend
this file system was unsuccessful. Make more space available, then retry
this operation.
6. Press Enter.
7. Look at the error messages, if any, at the end of the command execution
when the command status changes to failed. It is recommended that you look
at your smit.log even if the command status reports OK, since there may be
filesets that you wanted to install that the system did not attempt to install.
Chapter 4. System and software installation 93
Committing applied updates
To commit an applied software update:
1. Use the SMIT fast pathsmitty install_commit
A screen similar to Figure 4-9 is shown.
Figure 4-9 Commit Applied Software Updates (Remove Saved Files) menu
2. In the SOFTWARE to install field, either enter the name, if you know what you
want to commit, or press F4 to get a list of all the available software. Press
Enter once you have selected the products you want to commit. Leaving the
SOFTWARE name field to all will commit all applied filesets installed on the
system.
3. Press Enter. The system reports that the software is about to be committed,
commits the software, and then removes the copies from the
/usr/lpp/PackageName directory.
Rejecting applied updates
In order to reject a service update that you have installed:
1. Use the SMIT fast path smitty install_reject
A screen similar to Figure 4-10 on page 94 is shown.
94 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 4-10 Reject Applied Software Updates (Use Previous Version) menu
2. Press F4 on the SOFTWARE name field to select the software update you
want to reject. All the software updates that are in the applied state will be
listed. Select the update that you want to reject, and press Enter.
Removing installed software
You can remove installed and committed software by using the SMIT fast path:
1. smitty install_remove
A screen similar to Figure 4-11 on page 95 is shown.
Chapter 4. System and software installation 95
Figure 4-11 Remove Installed Software menu
2. Press F4 in the SOFTWARE name field to get a list of all the software that is
installed on your system. Select the software you want to remove by pressing
F7, followed by Enter, once you are done.
3. The PREVIEW only? (remove operation will NOT occur) field is yes by default.
This allows you to preview any remove operations and confirm your choices
before you actually do the remove action.
4. Once you are sure that you want to remove this software, change PREVIEW
only? (remove operation will NOT occur) field to no, and press Enter. This will
remove all the software that you have selected to be removed.
4.7 Maintaining optional software (applying updates)
Software that is distributed to fix a problem in a product is called an update. All
software products have a version number and a release number that identify the
release level of the product. In addition to this, product updates are assigned a
modification level number and a fix level number to identify the level of the
update. See Section 4.4, “Understanding maintenance levels” on page 82 for
information on maintenance levels.
96 IBM ^ Certification Study Guide - pSeries AIX System Administration
Suppose that you have your system currently running 4.3.2.0, and all the filesets
are at 4.3.2.0 maintenance level. IBM has just released a latest maintenance
level for systems on 4.3.2.0. You have to upgrade your system to bring it to the
latest maintenance level.
Bringing a system to the latest maintenance level involves a number of steps that
are listed below:
Listing the maintenance level of the software
Downloading fixes
Displaying and updating installed software to the latest level
4.7.1 Listing the maintenance level of software
The lslpp command displays information about installed filesets or fileset
updates. The most common flags used with the lslpp command are listed in
Tabl e 4-3:
Table 4-3 Command flags for lslpp
In order to see what maintenance level your filesets are currently on, use the
command:
lslpp -l
This will list all the software that is installed on your system showing the current
maintenance level. The output will look similar to the following:
Fileset Level State Description
----------------------------------------------------------------------------
Path: /usr/lib/objrepos
IMNSearch.bld.DBCS 2.3.1.0 COMMITTED NetQuestion DBCS Buildtime
Modules
IMNSearch.bld.SBCS 2.3.1.0 COMMITTED NetQuestion SBCS Buildtime
Modules
IMNSearch.msg.en_US.rte.com
Flag Description
-l Displays the name, most recent level, state, and description of the
specified fileset.
-f Displays the names of the files added to the system during installation
of the specified fileset.
-h Displays the installation and update history information for the
specified fileset.
-a Displays all information about filesets specified when combined with
other flags. Cannot be used with the -f flag.
Chapter 4. System and software installation 97
2.3.1.0 COMMITTED Text Search Messages - U.S.
English
IMNSearch.rte.DBCS 2.3.1.0 COMMITTED NetQuestion DBCS Search Engine
IMNSearch.rte.SBCS 2.3.1.0 COMMITTED NetQuestion SBCS Search Engine
IMNSearch.rte.client 2.3.1.0 COMMITTED Text Search Client
IMNSearch.rte.com 2.3.1.0 COMMITTED Text Search Client/Server
Shared Files
IMNSearch.rte.httpdlite 2.0.0.2 COMMITTED Lite NetQuestion Local Web
Server
IMNSearch.rte.server 2.3.1.0 COMMITTED Text Search Server
Java130.rte.bin 1.3.0.5 COMMITTED Java Runtime Environment
Executables
Java130.rte.lib 1.3.0.5 COMMITTED Java Runtime Environment
Libraries
To list the individual files that are installed with a particular fileset, use the
command:
lslpp -f
For example, if you wanted to display all files installed with the bos.64bit fileset,
you would enter:
# lslpp -f bos.64bit
Fileset File
----------------------------------------------------------------------------
Path: /usr/lib/objrepos
bos.64bit 5.1.0.0 /usr/lib/methods/cfg64
/usr/ccs/bin/shlap
/usr/ccs/bin/usla64
/usr/lib/drivers/syscalls64.ext
/usr/ccs/bin/usla
/usr/ccs/bin/shlap64
Path: /etc/objrepos
bos.64bit 5.1.0.0 NONE
To list the installation and update history of filesets, use the command:
lslpp -h
For example, if you wanted to see when the bos.sysmgt.trace fileset was last
updated, you would enter:
# lslpp -h bos.sysmgt.trace
Fileset Level Action Status Date Time
--------------------------------------------------------------------------
Path: /usr/lib/objrepos
bos.sysmgt.trace
4.3.3.0 COMMIT COMPLETE 08/04/01 11:00:28
4.3.3.11 COMMIT COMPLETE 08/04/01 17:00:13
98 IBM ^ Certification Study Guide - pSeries AIX System Administration
Path: /etc/objrepos
bos.sysmgt.trace
4.3.3.0 COMMIT COMPLETE 06/15/00 09:57:33
4.3.3.11 COMMIT COMPLETE 06/16/00 11:19:14
4.7.2 Downloading fixes
IBM provides a site on the Internet where you may freely download AIX-related
fixes. The current anonymous FTP server is service.software.ibm.com. This
site has a variety of mirrors that are listed when you FTP to the site.
To help customers browse and download fixes stored at the fix sites, IBM has
released a freely available service tool called FixDist. FixDist is a tool designed to
enable customers to select and download a fix and any necessary requisite fixes.
AIX 5L users should check the Web for special tools used for this Version.
FixDist and the user guide are available using an anonymous FTP from the
server listed above or its mirrors. This site is also accessible through the URL
http://service.software.ibm.com.
Once you have installed and set up the FixDist tool on your AIX system, the next
step is to download the updates you want. On the command line, enter:
1. fixdist
A screen similar to Figure 4-12 is shown.
Figure 4-12 fixdist - Step 1
Chapter 4. System and software installation 99
In this case, you have chosen to download all the PTFs to the /ptf file system.
It is possible that you might be running a number of different releases of AIX
in your environment. In this case, it is recommended that you keep your
update downloads in different directories naming them according to the
release level. In this example, set the target directory field to the /ptf directory.
2. Select Generally Available Fixes to list what updates are available from IBM.
A screen similar to Figure 4-13 is shown.
Figure 4-13 fixdist - Step 2
3. Select the updates you want to apply to your system by clicking on the name
of the update/fix. In this case, since you are applying the latest updates for
AIX Version 4.3.1.0, select the latest fixes for 4.3.1.0.
4. After you have selected the updates you want, you have the option to preview
what will be downloaded, the estimated size of the images that will be
downloaded, and other features. It is a good practice to download all your
fixes into one file system.
FixDist will download all the fixes in the directory given at the start of the FixDist
process as shown in Figure 4-12. All the files are downloaded in the BFF format.
BFF stands for Backup File Format, which means that the file was created using
the AIX backup command and can be read using the AIX restore command. In
addition to the .bff files, .info files are also downloaded that give a brief summary
of what the fileset is for and what has been fixed by this fileset.
100 IBM ^ Certification Study Guide - pSeries AIX System Administration
If you apply updates frequently and keep all the updates in the same directory,
then the .toc file might be outdated. The command installp uses the .toc file to
carry out installations. To have the correct and latest software installed when you
actually do the installation, it is recommended that you rebuild the .toc file. This
can be done by using the inutoc command. The general syntax of the inutoc
command is:
inutoc [Directory name]
The inutoc command creates a .toc file for directories that have backup format
file install images. This command is used automatically by the installp
command or the install script if no .toc file is present.
4.7.3 Displaying and updating installed software to the latest level
Once you have downloaded all the fixes into the /ptf directory, the next step is to
install them and bring your system to the latest maintenance level. In this section,
the following procedures are discussed:
Displaying an individual fix (instfix command)
Installing an individual fix by APAR
Updating all filesets to the latest level
Displaying an individual fix (instfix command)
You can download an individual fix using FixDist following the same procedure
given in Section 4.7.2, “Downloading fixes” on page 98.
In order to determine if a fix is installed on your system or to install a fix, use the
instfix command. The general syntax of the instfix command is as follows:
instfix [ -T ] [ -s String ] [ -S ] [ -k Keyword | -f File ] [ -p ]
[ -d Device ] [ -i [ -c ] [ -q ] [ -t Type ] [ -v ] [ -F ] ] [ -a ]
The general flags used with instfix command are given in Table 4-4.
Table 4-4 Command flags for instfix
Flag Description
-a Displays the symptom text associated with a fix. Can be used with the
-f, -i, and -k flags.
-d Device Specifies the input device. Required for all flags except -i and -a.
-f FileName Specifies the input file FileName containing keywords or fixes. The -T
flag produces a suitable input file format for the -f flag.
-i Displays whether fixes or keywords are installed.
Chapter 4. System and software installation 101
The instfix command allows you to install a fix or set of fixes without knowing
any information other than the Authorized Program Analysis Report (APAR)
number or other unique keywords that identify the fix.
A fix can have a single fileset or multiple filesets. Fix information is organized in
the Table of Contents (TOC) on the installation media. After a fix is installed, fix
information is kept on the system in a fix database.
To list fixes that are on a CD-ROM in /dev/cd0, enter the command:
# instfix -T -d /dev/cd0
IX75893
To determine if APAR IX75893 is installed on the system, enter the command:
# instfix -ik IX75893
Not all filesets for IX75893 were found.
To examine information about APAR IX75893 and what it does, enter the
command:
# instfix -aik IX75893
IX75893 Abstract: Process memory is made read-only unnecessarily
IX75893 Symptom Text:
Resource handler routines not being able to store to process
memory when a process is dumping core.
----------------------------
Not all filesets for IX75893 were found.
To list what maintenance levels have been installed on your system with the
instfix command, enter the command:
# instfix -i | grep ML
All filesets for AIX43ML were found.
-k Keyword Specifies an APAR number or keyword to be installed. Multiple
keywords can be entered. A list of keywords entered with the -k flag
must be contained in quotation marks and separated with spaces.
-s String Searches for and displays fixes on the media containing a specified
string.
-T Displays the list of fixes on the media.
-v Used with the -i flag to specify verbose mode. Displays information
about each fileset associated with a fix or keyword.
Flag Description
102 IBM ^ Certification Study Guide - pSeries AIX System Administration
All filesets for 4.3.0.0_AIX_ML were found.
Not all filesets for 4.3.1.0_AIX_ML were found.
To install APAR IX75893 from /dev/cd0, enter the command:
# instfix -k IX75893 -d /dev/cd0
You can also use SMIT to determine what fixes are installed on your system. Use
the SMIT fast path:
1. smitty show_apar_stat
A screen similar to Figure 4-14 is shown.
Figure 4-14 Show Fix (APAR) Installation Status menu
2. Press F4 in the FIX ID field to get a list of all the fixes that are installed on the
system. The output from this command is similar to the instfix -iv
command.
Note: By default, when instfix is run from the command line, the command
uses stdout and stderr for reporting. If you want to generate an installation
report, you will need to redirect the output. For example:
# instfix -aik IX75893 >/tmp/instfix.out 2>/tmp/instfix.err
Chapter 4. System and software installation 103
Installing an individual fix by APAR
To install the fixes using SMIT, use the SMIT fast path:
1. smitty instfix or smitty update_by_fix
2. In the INPUT device/directory for the software field, enter the name of the
device (or directory if you downloaded the fixes to your system) from which to
install the fixes, and press Enter. A screen similar to Figure 4-15 is shown.
Figure 4-15 Update Software by Fix (APAR) menu
3. In the FIXES to Install field, press F4 to get a list of fixes that are available on
the media and select the fixes you want to install.
4. Press Enter.
The system will update the maintenance level of the fileset you selected and
upon completion you will have successfully updated the maintenance level of
your software.
Updating all filesets to the latest level
To install all new fixes that are available through IBM, use the fast path:
1. smitty update_all
104 IBM ^ Certification Study Guide - pSeries AIX System Administration
A screen similar to Figure 4-16 is shown.
Figure 4-16 Update Installed Software to Latest Level (Update All) menu
2. In the INPUT device/directory for software field, enter the name of the device
(or directory if you have fixes on your hard disk) from which installation will be
carried out.
3. Press Enter.
Chapter 4. System and software installation 105
A screen similar to Figure 4-17 is shown.
Figure 4-17 Update Installed Software to Latest Level (Update All) menu - more
4. It is best to set the PREVIEW only? (update operation will NOT occur) field to
YES by pressing the Tab key. The Preview option makes a dry run of the task
you are trying to perform and reports any failures that might be encountered
when you do the actual installation. This will ensure that your installation does
not fail.
Once you are sure that there are no prerequisites that you are missing, you can
do the actual installation. This procedure will update your software to the latest
maintenance level.
To view the new maintenance level of your software, enter on the command line:
# lslpp -l
This will show you the latest maintenance level of the filesets including those you
just updated.
106 IBM ^ Certification Study Guide - pSeries AIX System Administration
4.8 Creating installation images on a hard disk
Installable image files (or installation packages) can be copied to a hard disk for
use in future installations. These image files will be copied from your installation
media (tape or diskette) to a directory on the disk, so that they may be installed
later using the disk directory as the input device. These files will be copied to the
directory named /usr/sys/inst.images.
To create installation images on your hard disk, use the SMIT fast path:
1. smitty bffcreate
A screen similar to Figure 4-18 is shown.
Figure 4-18 Copy Software to Hard Disk for Future Installation menu
2. In the INPUT device/directory for software field, enter the name of your
source that will be used to copy the images and press Enter.
3. On the next screen, press F4 on the Software package to copy field to get a
list of the software available on the media. Select the installation images you
want to copy to your hard disk and press Enter.
4. All the images will be copied to your hard disk in the /usr/sys/inst.images
directory, and the /usr/sys/inst.images/.toc file is updated.
Chapter 4. System and software installation 107
For future installations, enter the /usr/sys/inst.images directory in the INPUT
device / directory for software field. If for some reason your .toc file becomes
corrupted, you will receive an error either in SMIT or the command line,
depending on what are you using, similar to:
0503-005 The format of .toc file is invalid
In this case, simply use the inutoc /usr/sys/inst.images/.toc command to
recreate your .toc file.
This method of creating installation images is helpful in situations where the
software you are trying to install has co-requisites that are on different media and
your installation process does not let you change the media it is currently
processing. In such situations, your installation will fail; therefore, it is
recommended to have all the prerequisites and co-requisites reside in one
directory and then do the installation.
To get co-requisites that are on different media, use the smitty bffcreate fast
path to copy required filesets from the first CD-ROM to the hard disk in
/usr/sys/inst.images. Then, use the smitty bffcreate fast path to copy the
required filesets from the additional CD-ROMs to the hard disk in
/usr/sys/inst.images. After all the required filesets have been copied to the hard
disk, use the installp command or the smitty install_latest fast path to
install the software. Since the system reads the /usr/sys/inst.images/.toc file for
installation, and all the filesets are local to the hard disk, it will not prompt you for
a CD-ROM or fail the installation.
4.9 Alternate disk installation
Alternate disk installation, available in AIX Version 4.3 and later versions, allows
for system installation on a system while it is still up and running, which produces
install or upgrade downtime to be decreased considerably. It also allows large
facilities to manage an upgrade, because systems can be installed over a longer
period of time, while the systems are still running at the existing version. The
switch over to the new version can then happen with a simple reboot.
4.9.1 Filesets required
Alternate disk installation requires some filesets to be installed before you are
able to use the alternate disk installation functions. The
bos.alt_disk_install.boot_images filesets must be installed for alternate disk
mksysb installation, if Network Install Management (NIM) is not being used. The
bos.alt_disk_install.rte fileset must be installed to clone rootvg.
108 IBM ^ Certification Study Guide - pSeries AIX System Administration
Once you have installed these filesets, the alternate disk installation functions
are available to you in the Software Installation and Maintenance menu. Use the
SMIT fast path:
smitty alt_install
A screen similar to Figure 4-19 is shown.
Figure 4-19 Alternate Disk Installation menu
Alternate disk installation can be used in one of two ways:
Cloning the current running rootvg to an alternate disk.
Installing a mksysb image on another disk.
4.9.2 Alternate disk rootvg cloning
Cloning the rootvg to an alternate disk can have many advantages.
Having an online backup available in case of disaster. Keeping an on-line
backup requires that an extra disk or disks to be available on the system.
Applying new maintenance levels or updates. A copy of the rootvg is made to
an alternate disk, then updates are applied to that copy. Finally, the boot list is
updated to boot from the new device. The system runs uninterrupted during
this time. When it is rebooted, the system will boot from the newly updated
rootvg for testing. If updates cause problems, the old rootvg can be retrieved
by resetting the bootlist and rebooting.
Chapter 4. System and software installation 109
To clone your rootvg to a new disk, do the following procedure:
1. Use the SMIT fast path smitty alt_clone
A screen similar to Figure 4-20 is shown.
Figure 4-20 Clone the rootvg to an Alternate Disk menu
2. In the Target Disk(s) to install field, enter the name of the disk you want to use
for making the clone. The target disk should be a stand-alone disk not
belonging to a volume group. In addition to this, SSA disks cannot be used as
your target disks.
3. The Phases to execute field defaults to all. Accept the default, for now.
4. In the Exclude list field, you can create a file that will contain the names of all
the files and directories that you do not want to be copied to your cloned
system.
5. Specify the name of any additional bundles or filesets and fixes that you want
to install in the Bundle to install and Fix to Install fields. The use of these fields
allows service to be installed as part of the clone process.
6. Specify the name of the input device in case you have selected to install any
additional software in the Directory or Device with images field.
7. If you want your system to start from your alternate rootvg on the next system
start-up, set the Set the bootlist to boot from this disk on next boot to YES.
8. Press Enter.
110 IBM ^ Certification Study Guide - pSeries AIX System Administration
The following sequence of output is shown in SMIT while the system is cloning to
the new disk:
Calling mkszfile to create new /image.data file.
Checking disk sizes
Creating cloned rootvg volume group and associated logical volumes
Creating Logical volume alt_hd5
Creating Logical volume alt_hd6
Creating Logical volume alt_hd8
Creating Logical volume alt_hd4
Creating Logical volume alt_hd2
Creating Logical volume alt_hd9var
Creating Logical volume alt_hd3
Creating Logical volume alt_hd1
Creating /alt_inst / file system
Creating /alt_inst/usr file system
Creating /alt_inst/var file system
Creating /alt_inst/tmp file system
Creating /alt_inst/home file system
Generating a list of files
for backup and restore into the alternate file system ...
Backing up the rootvg files and restoring them to the
alternate File Systems
Modifying ODM on cloned disk
Building boot image on cloned disk
Forced umount of /alt_inst/home
Forced umount of /alt_inst/tmp
Forced umount of /alt_inst/var
Forced umount of /alt_inst/usr
Forced umount of /alt_inst/
Changing logical volume names in Volume Group Descriptor Area
Fixing Logical Volume control blocks
Fixing File system super blocks
Bootlist is set to the bootdisk:hdisk1
By default, the bootlist will be set to the new cloned rootvg for the next reboot.
This completes the cloning of the rootvg using the alt_disk_install command.
4.9.3 Alternate mksysb install
An alternate mksysb install involves installing a mksysb image that has already
been created from another system onto an alternate disk of the target system.
The mksysb image (AIX Version 4.3 or later) would be created on a system that
was either the same hardware configuration as the target system or would have
all the device and kernel support installed for a different machine type or platform
or different devices.
Chapter 4. System and software installation 111
To create the alternate mksysb system, use the SMIT fast path:
1. smitty alt_mksysb
A screen similar to Figure 4-21 is shown.
Figure 4-21 Install mksysb on an Alternate Disk menu
2. Enter the name of the disk on which you want to install the mksysb in the
Target Disk(s) to install field.
3. Enter the name of the device or the image name from which you will be
restoring the mksysb in the Device or image name field.
4. Press Enter.
Once the mksysb image is restored to the new disk, the system reboots from the
new alternate rootvg. This completes your alternate mksysb installation.
112 IBM ^ Certification Study Guide - pSeries AIX System Administration
4.10 Quiz
The following certification assessment questions help verify your understanding
of the topics discussed in this chapter.
1. An AIX installation has just completed. Maintenance Level 6 has been applied
to the BOS. Which command will show all installed maintenance levels
concurrently?
A. oslevel -a
B. lslpp -l | grep AIX
C. smitty show_apar_stat
D. instfix -i | grep ML
2. How would an administrator verify that the system has all required
prerequisite fixes prior to installing a software fix?
A. Use the lsprereq command.
B. Use installp with the preview option.
C. View the .toc file in the root directory.
D. Use the inutoc command to update the .toc file.
3. It has been determined that fix IX39714 needs to be applied to a server as
soon as possible. How can this fix be obtained if the system has Internet
connectivity?
A. Use the fixdist utility to download the fix.
B. FTP the fix from fixes.pseries.ibm.com.
C. Send an E-mail to fixes.pseries.ibm.com with IX39714 in the subject line.
D. Use the Web-Based System Manager to download the fix.
The following are additional questions created by the authors to further test your
understanding of the topics.
1. During the first reboot after the AIX 5L Version 5.1 operating system
installation process has completed, what is the first screen the administrator
will see?
A. Login prompt
B. Root shell prompt
C. Installation Assistant
D. Configuration Assistant
Chapter 4. System and software installation 113
2. Which of the following commands lists the current fix level of the
bos.net.nfs.client fileset?
A. lsfs bos.net.nfs.client
B. lslpp -l bos.net.nfs.client
C. lppchk -l bos.net.nfs.client
D. installp -ver bos.net.nfs.client
3. Which of the following commands can be used to verify the success of an
operating system upgrade?
A. oslevel
B. lslpp -h bos.obj
C. what_fileset -v
D. lsattr -Vl bos.rte
4. If bos.up displays on your machine as being at 4.3.1.7, what is the
modification level?
A. 1
B. 3
C. 4
D. 7
4.10.1 Answers
The following answers are for the assessment quiz questions.
1. D
2. B
3. A
The following answers are for the additional quiz questions.
1. D
2. B
3. A
4. A
114 IBM ^ Certification Study Guide - pSeries AIX System Administration
4.11 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Try to the run installp command twice at the same time on one system and
see what happens.
2. You have just installed a new release of the operating system, determine the
operating system level of your system.
3. What is a fileset, package, bundle? Explain.
4. Your root file system is behaving strangely; therefore, you decide to do a
preserve install. However, you do not want to overwrite your /var file system.
What can be done to prevent this? Perform the preserve install and save your
/var file system as is.
5. Your installation is failing repeatedly because of missing prerequisites. How
will you use preview option to obtain all the prerequisite information in SMIT?
6. What are the methods available to you to upgrade your system to the latest
release/maintenance level yet minimize the downtime?
7. If prerequisites from two install medias point to each other, what is the best
method that you can use to complete the installation without errors?
8. What are the different methods of installation available to you for installing a
base operating system?
9. Use the installation assistant to set the time and paging size on your system.
10.Update your system to bring all the filesets to the latest fix level.
11.IBM has just announced a new fix pack. Obtain the fixpack from the IBM FTP
site and apply the fixes to upgrade your system to the latest fix level.
12.Determine the latest fix level on your system.
13.Find out the latest fix level of a licensed program, filesets, and so on.
14.How do you use the installp command, and what are the different options
that are available to you?
15.You have just downloaded the latest fix from IBM, but before you go into
production, you want to test-run the system with the latest fix pack installed.
Use the alternate disk install to make a replica of your system and test out the
changes with the fix pack installed.
16.Find out what are the different filesets you have and their state using the
installp command. Next, commit any applied software and remove any
fileset that you think is not required. Also, apply a fix pack and then reject the
changes made by this fixpack.
Chapter 4. System and software installation 115
17.Download an individual fix and use SMIT to install the fix.
18.Download any package from your installation media to your disk, create a new
table of contents for the /usr/sys/inst.images directory, and install the package
using SMIT.
116 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 117
Chapter 5. Object Data Manager
The ODM has many purposes. Its primary functions are to maintain the RISC
System/6000 configuration, associated devices, and the vital product database.
In addition, it provides a more robust, secure, and sharable resource than the
ASCII files previously used in AIX.
System data managed by the ODM includes:
Device configuration information
Display information for SMIT (menus, selectors, and dialogs)
Vital product data for installation and update procedures
Communications configuration information
System resource information
Most system object classes and objects are stored in the /usr/lib/objrepos
directory; however, ODM information is stored in three directories as follows:
/usr/lib/objrepos
/usr/share/lib/objrepos
/etc/objrepos
5
118 IBM ^ Certification Study Guide - pSeries AIX System Administration
The basic components of the ODM are object classes and objects. To manage
object classes and objects, you use the ODM commands and subroutines.
Specifically, you use the create and add features of these interfaces to build
object classes and objects for storage and management of your own data.
A summary of the ODM concepts is provided in Table 5-1.
Table 5-1 ODM Concepts
An object class comprises one or more descriptors. Values are associated with
the descriptors of an object when the object is added to an object class. The
descriptors of an object and their associated values can be located and changed
with the ODM facilities.
In the area of device configuration, the ODM contains information about all
configured physical volumes, volume groups, and logical volumes. This
information mirrors the information found in the VGDA. The process of importing
a VGDA, for example, involves copying the VGDA data for the imported volume
group into the ODM. When a volume group is exported, the data held in the ODM
about that volume group is removed from the ODM database.
5.1 ODM commands
You can create, add, change, retrieve, display, and delete objects and object
classes with ODM. ODM commands are entered on the command line.
Item Definition Similar to Similar to
ODM Object A member of a defined
ODM object class. An
entity that requires
management and
storage of data.
An element of an
array structure.
One of the fixed
format records.
Object Class A stored collection of
objects with the same
definition.
An array of
C-Language
structures.
A file with fixed
format records.
ODM Database A stored collection of
ODM object classes.
A collection of
structure arrays.
A directory of files.
Chapter 5. Object Data Manager 119
These commands are:
odmadd Adds objects to an object class. The odmadd command takes an
ASCII stanza file as input and populates object classes with
objects found in the stanza file.
odmchange Changes specific objects in a specified object class.
odmcreate Creates empty object classes. The odmcreate command takes an
ASCII file describing object classes as input and produces C
language .h and .c files to be used by the application accessing
objects in those object classes.
odmdelete Removes objects from an object class.
odmdrop Removes an entire object class.
odmget Retrieves objects from object classes and puts the object
information into odmadd command format.
odmshow Displays the description of an object class. The odmshow
command takes an object class name as input and puts the
object class information into odmcreate command format.
5.2 Example of an object class for an ODM database
The following is an example of the object class definition for the Customized
Device Database (CuDv):
# odmshow CuDv
class CuDv {
char name[16]; /* offset: 0xc ( 12) */
short status; /* offset: 0x1c ( 28) */
short chgstatus; /* offset: 0x1e ( 30) */
char ddins[16]; /* offset: 0x20 ( 32) */
char location[16]; /* offset: 0x30 ( 48) */
char parent[16]; /* offset: 0x40 ( 64) */
char connwhere[16]; /* offset: 0x50 ( 80) */
link PdDv PdDv uniquetype PdDvLn[48]; /* offset: 0x60 ( 96) */
};
/*
Note: ODM commands should be used only when traditional methods of
system maintenance, such as SMIT, are ineffective. For a beginning
system administrator, it is recommended that you perform additional
reading and exercises before using these commands. Incorrect use of
these commands may result in a disabled system. The ODM commands
are described here for introductory purposes.
120 IBM ^ Certification Study Guide - pSeries AIX System Administration
descriptors: 8
structure size: 0x98 (152) bytes
data offset: 0x20001cd8
population: 50 objects (50 active, 0 deleted)
*/
5.3 Quiz
The following are questions created by the authors to further test your
understanding of the topics.
1. A system administrator wishes to determine if a newly configured tape drive is
correctly added to the ODM database. Which command would the
administrator use?
A. odmshow
B. odmadd
C. odmget
D. odmcreate
2. The ODM is located in:
A. /etc/objrepos
B. /usr/lib/objrepos
C. /usr/share/lib/objrepos
D. All of the above
5.3.1 Answers
The following answers are for the quiz questions.
1. C
2. D
5.4 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. List the uses of the ODM.
2. Using the correct ODM facility, determine the format of the Predefined Device
Database (PdDv).
© Copyright IBM Corp. 2001 121
Chapter 6. Storage management, LVM,
and file systems
In this chapter, storage management, Logical Volume Management (LVM), and
file system support issues are covered. The basic tasks that require
understanding are broken down into separate sections.
6
122 IBM ^ Certification Study Guide - pSeries AIX System Administration
6.1 Logical volume storage concepts
The five basic logical storage concepts are: Physical volumes, volume groups,
physical partitions, logical volumes, and logical partitions. The relationships
among these concepts are provided in Figure 6-1.
Figure 6-1 Relationship between logical storage components
The following can be said regarding Figure 6-1:
Each individual fixed-disk drive is called a physical volume (PV) and has a
name (for example: hdisk0, hdisk1, or hdisk2).
All physical volumes belong to one volume group (VG) named rootvg.
All of the physical volumes in a volume group are divided into physical
partitions (PPs) of the same size.
Within each volume group, one or more logical volumes (LVs) are defined.
Logical volumes are groups of information located on physical volumes. Data
on logical volumes appear as contiguous to the user but can be discontiguous
on the physical volume.
Each logical volume consists of one or more logical partitions (LPs). Each
logical partition corresponds to at least one physical partition. If mirroring is
specified for the logical volume, additional physical partitions are allocated to
store the additional copies of each logical partition.
Chapter 6. Storage management, LVM, and file systems 123
Logical volumes can serve a number of system purposes (paging, for
example), but each logical volume that holds ordinary systems, user data, or
programs, contains a single journaled file system (JFS). Each JFS consists of
a pool of page-size (4 KB) blocks. In AIX Version 4.1 and later, a given file
system can be defined as having a fragment size of less than 4 KB (512
bytes, 1 KB, 2 KB).
After installation, the system has one volume group (the rootvg volume group),
consisting of a base set of logical volumes required to start the system, and any
other volume groups you specify to the installation script.
6.2 Logical Volume Manager
The set of operating system commands, library subroutines, and other tools that
allow you to establish and control logical volume storage is called the Logical
Volume Manager (LVM). The LVM controls disk resources by mapping data
between a more simple and flexible logical view of storage space and the actual
physical disks.
6.2.1 LVM configuration data
The data that describes the components of the LVM is not kept in one place. It is
important to understand that this descriptive data about volume groups, logical
volumes, and physical volumes is kept in several places.
Object Data Manager (ODM) database
The ODM database is the place where most of the AIX system configuration data
is kept. The ODM database contains information about all configured physical
volumes, volume groups, and logical volumes. This information mirrors the
information found in the VGDA. For example, the process of importing a VGDA
involves automatically copying the VGDA data for the imported volume group into
the ODM. When a volume group is exported, the data held in the ODM about that
volume group is removed from the ODM database.
The ODM data also mirrors the information held in the Logical Volume Control
Block.
124 IBM ^ Certification Study Guide - pSeries AIX System Administration
Volume Group Descriptor Area (VGDA)
The VGDA, located at the beginning of each physical volume, contains
information that describes all the logical volumes and all the physical volumes
that belong to the volume group of which that physical volume is a member. The
VGDA is updated by almost all the LVM commands. The VGDA makes each
volume group self-describing. An AIX system can read the VGDA on a disk, and,
from that, can determine what physical volumes and logical volumes are part of
this volume group.
Each disk contains at least one VGDA. This is important at vary on time. The
time stamps in the VGDAs are used to determine which VGDAs correctly reflect
the state of the volume group. VGDAs can get out of sync when, for example, a
volume group of four disks has one disk failure. The VGDA on that disk cannot be
updated while it is not operational. Therefore, you need a way to update this
VGDA when the disk comes online, and this is what the vary on process will do.
The VGDA is allocated when the disk is assigned as a physical volume (with the
command mkdev). This just reserves a space for the VGDA at the start of the disk.
The actual volume group information is placed in the VGDA when the physical
volume is assigned to a volume group (using the mkvg or extendvg commands).
When a physical volume is removed from the volume group (using the reducevg
command), the volume group information is removed from the VGDA.
Volume Group Status Area (VGSA)
The VGSA contains state information about physical partitions and physical
volumes. For example, the VGSA knows if one physical volume in a volume
group is unavailable.
Both the Volume Group Descriptor Area and the Volume Group Status Area have
beginning and ending time stamps that are very important. These time stamps
enable the LVM to identify the most recent copy of the VGDA and the VGSA at
vary on time.
The LVM requires that the time stamps for the chosen VGDA be the same as
those for the chosen VGSA.
Logical Volume Control Block (LVCB)
The LVCB is located at the start of every logical volume. It contains information
about the logical volume and uses a few hundred bytes.
Chapter 6. Storage management, LVM, and file systems 125
The following example shows the use of the getlvcb command to display the
information held in the LVCB of logical volume hd2:
# getlvcb -TA hd2
AIX LVCB
intrapolicy = c
copies = 1
interpolicy = m
lvid = 00011187ca9acd3a.7
lvname = hd2
label = /usr
machine id = 111873000
number lps = 72
relocatable = y
strict = y
type = jfs
upperbound = 32
fs = log=/dev/hd8:mount=automatic:type=bootfs:vol=/usr:free=false
time created = Tue Jul 27 13:38:45 1993
time modified = Tue Jul 27 10:58:14 1993
6.2.2 Disk quorum
Each physical disk in a volume group has at least one VGDA/VGSA. The number
of VGDAs contained on a single disk varies according to the number of disks in
the volume group as shown in Table 6-1.
Table 6-1 VGDA allocation
A quorum is a state in which 51 percent or more of the physical volumes in a
volume group are accessible. A quorum is a vote of the number of Volume Group
Descriptor Areas and Volume Group Status Areas (VGDA/VGSA) that are active.
A quorum ensures data integrity in the event of a disk failure.
When a volume group is created onto a single disk, it initially has two
VGDA/VGSA areas residing on the disk. If a volume group consists of two disks,
one disk still has two VGDA/VGSA areas, but the other disk has one
VGDA/VGSA. When the volume group is made up of three or more disks, then
each disk is allocated just one VGDA/VGSA.
Condition VGDA allocation
Single PV in a volume group Two VGDAs on one disk.
Two PVs in a volume group Two VGDAs on the first disk, one VGDA on the
second disk.
Three or more PVs in a volume group One VGDA on each disk
126 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 6-2 shows that the quorum is lost when enough disks and their
VGDA/VGSA areas are unreachable so that a 51% majority of VGDA/VGSA
areas no longer exists.
Figure 6-2 Disk quorum
When a quorum is lost, the volume group varies itself off so that the disks are no
longer accessible by the Logical Volume Manager (LVM). This prevents further
disk I/O to that volume group so that data is not lost or assumed to be written
when physical problems occur. Additionally, as a result of the vary off, the user is
notified in the error log that a hardware error has occurred and service must be
performed.
This has implications when you want to use disk mirroring to ensure high
availability. In a two disk mirrored system, if the first disk fails, then you have lost
66 percent of your VGDAs, and the entire volume group becomes unavailable.
This defeats the purpose of mirroring. For this reason, three or more (and
generally an odd number) disk units provide a higher degree of availability and
are highly recommended where mirroring is desired.
Note: There is the ability to turn off disk quorum protection on any volume
group. Turning off quorum protection allows a volume group to remain
online even when a quorum or majority of its VGDAs are not online. This
would allow the volume group to remain online in the situation described
previously. This capability provides for a less expensive mirroring solution
but does carry the risk of data loss as, after a disk failure, data is
accessible but no longer mirrored.
Chapter 6. Storage management, LVM, and file systems 127
6.2.3 Disk mirroring
Disk mirroring is the association of two or three physical partitions with each
logical partition in a logical volume. When the data is written onto the logical
volume, it is also written to all the physical partitions that are associated with the
logical partition. Therefore, mirroring of data increases the availability of data.
AIX and the logical volume manager provide a disk mirroring facility at a logical
volume level. If mirroring is established, this can be done when a logical volume
is created.
The mklv command allows you to select one or two additional copies for each
logical volume. Mirroring can also be added to an existing logical volume using
the mklvcopy command.
The following mirroring factors can further improve the data availability:
The number of copies of data: Three copies of the data are more reliable than
keeping only two copies.
Location of the copies: Allocating the copies of a logical partition on different
physical volumes is more reliable than allocating the copies on the same
physical volume. This is because one of the most common error modes for
disk subsystems is the loss of an individual physical disk. Copies can also be
located across different disk adapters to further enhance isolation from
failures.
The mirrorvg command
The mirrorvg command mirrors all the logical volumes on a given volume group.
This same function may also be accomplished manually if you run the mklvcopy
command for each individual logical volume in a volume group. As with mklvcopy,
the target physical drives to be mirrored with data must already be members of
the volume group. This command only applies to AIX Version 4.2.1 or later.
The following is the syntax for the mirrovg command:
mirrorvg [ -S | -s ] [ -Q ] [ -c Copies] [ -m ] VolumeGroup
[ PhysicalVolume .. ]
By default, mirrorvg attempts to mirror the logical volumes onto any of the disks
in a volume group. The mirrorvg command mirrors the logical volumes using the
default settings of the logical volume being mirrored. If you wish to violate mirror
strictness or affect the policy by which the mirror is created, you must execute the
mirroring of all logical volumes manually with the mklvcopy command.
128 IBM ^ Certification Study Guide - pSeries AIX System Administration
Alternatively, you can also use the SMIT fast path command, smitty mirrorvg, to
do the mirroring of volume groups.
The following examples show the use of the mirrorvg command:
To triply mirror a volume group, run the following command:
mirrorvg -c 3 workvg
The logical partitions in the logical volumes held on workvg now have three
copies.
To get default mirroring of rootvg, run the following command.
mirrorvg rootvg
The rootvg volume group now has two copies of data.
To replace a failed disk drive in a mirrored volume group, run the following
commands:
unmirrorvg workvg hdisk7
reducevg workvg hdisk7
rmdev -l hdisk7 -d
Replace the failed disk drive with a new one, and name it hdisk7 by executing
the following commands:
extendvg workvg hdisk7
mirrorvg workvg
Note: The mirrorvg command may take a significant amount of time before
completing because of complex error checking, the number of logical
volumes to mirror in a volume group, and the time to synchronize the new
mirrored logical volumes.
Note: Problems may occur when you attempt to place a disk back into the
original system if the disk is removed from a volume group, updated, and
then returned. There is no way to control which copy of the data will be
used to resynchronize the other copy.
If any LVM information is changed while the disk is in your backup
system, those changes will not be known to your primary system even if
the backup is used to resync the primary disk. LVM changes include:
Creating, removing, or expanding any file system, paging spaces, and
other logical volume.
Chapter 6. Storage management, LVM, and file systems 129
The following command will synchronize the newly created mirrors:
mirrorvg -S -c 3 workvg
The -c flag specifies the minimum number of copies that each logical volume
must have after the mirrorvg command finishes executing. The -S flag
returns the mirrorvg command immediately and performs a background
syncvg of the volume group. It will not be apparent when the mirrors are
synchronized, but they will be immediately used by the system when ready.
To create an exact mapped volume group, run the following command:
mirrorvg -m datavg hdisk2 hdisk3
The -m flag allows mirroring of logical volumes in the exact physical partition
order that the original copy is ordered.
Rootvg mirroring
When the rootvg mirroring has completed, the following three tasks must be
performed:
1. Run the bosboot command.
The bosboot command creates a boot file (boot image) from a RAM (Random
Access Memory) disk file system and a kernel. The bosboot command is
required to customize the bootrec of the newly mirrored drive.
2. Run the bootlist command.
The bosboot command always saves device configuration data for disk. It
does not update the list of boot devices in the NVRAM (nonvolatile random
access memory). The NVRAM list can be modified by using the bootlist
command.
3. Reboot the system.
Finally, the default of the mirrorvg command is for the quorum to be turned
off. To change the quorum on a rootvg volume group, the system must be
rebooted.
Note: By default in this example, mirrorvg will try to create two copies
for the logical volumes in workvg. It will try to create the new mirrors
onto the replaced disk drive. However, if the original system had been
triply mirrored, there may be no new mirrors created onto hdisk7, as
other copies may already exist for the logical volumes.
130 IBM ^ Certification Study Guide - pSeries AIX System Administration
Non-rootvg mirroring
When a non-rootvg volume group is mirrored, the quorum state is deactivated.
For the deactivation of the quorum to take effect, all open logical volumes must
be closed. Then vary off and vary on the volume group for the changes to take
effect.
If the vary on of the volume group is not performed, although the mirroring will
work correctly, no quorum changes will have taken effect.
Rootvg and non-rootvg mirroring
The system dump devices (primary /dev/hd6 and secondary /dev/sysdumpnull)
should not be mirrored. On some systems, the paging device and the dump
device are the same device. However, most users want the paging device
mirrored. When mirrorvg detects that a dump device and the paging device are
the same, the logical volume will be mirrored automatically.
If mirrorvg detects that the dump and paging devices are different logical
volumes, the paging device is automatically mirrored, but the dump logical
volume is not. The dump device can be queried and modified with the
sysdumpdev command.
6.3 Managing physical volumes
The following sections discuss adding a new disk drive, changing physical
volume characteristics, and monitoring the physical volumes.
6.3.1 Configuration of a physical volume
The following three methods can be used to configure a new disk drive. If the
LVM will use this disk, it must also be made a physical volume.
Method 1
This method is used when it is possible to shut down and power off the system
prior to attaching the disk.
Note: Do not reboot the machine if the bosboot command has
unsuccessfully created a boot disk. The problem should be resolved and
the bosboot command run to successful completion. The bosboot command
requires some space in the /tmp file system and the file system where the
target image is to reside, if there is such an image.
Chapter 6. Storage management, LVM, and file systems 131
When the system is booted after adding a disk drive, the cfgmgr command is run
by the system during booting, which will automatically configure the disk. After
boot-up is complete, log in as root, run lspv, and look for a new disk entry in the
output as shown in the following example.
hdisk1 none none
or
hdisk1 00005264d21adb2e none
The 16-digit number in the second column of the preceding example is the
physical volume identifier (PVID).
If the output shows the new disk with a PVID, it can be used by the LVM for
configuration. If the new disk does not have a PVID, then use the procedure
described in Section 6.3.2, “Making an available disk a physical volume” on
page 132 to allow the disk to be used by the LVM.
Method 2
This method may be used when it is not possible to shut down or power off the
system prior to attaching the disk. Perform the following tasks:
1. Run lspv to list the physical disks already configured on the system, as
shown in the following example:
# lspv
hdisk0 000005265ac63976 rootvg
2. To configure all newly detected devices on the system (including the new
disk), use the following command:
cfgmgr
3. Run lspv again and look for a new disk entry in the output as shown in the
following example:
hdisk1 none none
or
hdisk1 00005264d21adb2e none
Once you have determined the name of the newly configured disk, use the
procedure described in Section 6.3.2, “Making an available disk a physical
volume” on page 132 to allow the disk to be utilized by the LVM.
132 IBM ^ Certification Study Guide - pSeries AIX System Administration
Method 3
This method may be used when it is not possible to shut down or power off the
system prior to attaching the disk. This method requires the following information
about the new disk:
How the disk is attached (subclass).
The type of the disk (type).
Which system attachment the disk is connected to (parent name).
The logical address of the disk (where connected).
Use the following command to configure the disk and ensure that it is available as
a physical volume by using the pv=yes attribute.
mkdev -c disk -s subclass -t type -p parentname -w whereconnected -a
pv=yes
The pv=yes attribute makes the disk a physical volume and writes a boot record
with a unique physical volume identifier onto the disk (if it does not already have
one).
6.3.2 Making an available disk a physical volume
A new disk drive is usable only when assigned to a volume group. To be used by
the LVM, a disk must be configured as a physical volume. The following
command will change an available disk (hdisk1) to a physical volume by
assigning a physical volume identifier (PVID), if it does not already have one.
chdev -l hdisk1 -a pv=yes
This command has no effect if the disk is already a physical volume.
6.3.3 Modifying physical volume characteristics
This section discusses the two characteristics that can be changed for a physical
volume using the chpv command.
Setting allocation permission for a physical volume
The allocation permission for a physical volume determines if physical partitions
contained on this disk, which are not allocated to a logical volume yet, can be
allocated for use by logical volumes. Setting the allocation permission defines
whether or not the allocation of new physical partitions is permitted for the
specified physical volume.
Chapter 6. Storage management, LVM, and file systems 133
The following command is used to turn off the allocation permission for the
physical volume hdisk1:
chpv -a n hdisk1
To turn the allocation permission back on, use the following command:
chpv -a y hdisk1
Setting the availability of a physical volume
The availability of a physical volume defines whether any logical input/output
operations can be performed to the specified physical volume. Physical volumes
should be made unavailable when they are to be removed from the system or are
lost due to failure.
The following command is used to set the state of a physical volume to
unavailable:
chpv -v r pvname
This will quiesce all VGDA and VGSA copies on the physical volume, and the
physical volume will not take part in future vary on quorum checking. Also,
information about the specified volume will be removed from the VGDAs of the
other physical volumes in that volume group.
The following command will make a physical volume available to the system.
chpv -v a pvname
6.3.4 Removing physical volumes
A physical volume must be unconfigured before it can be removed from the
system. The following example shows how to unconfigure a physical volume
(hdisk1) and change its state from available to defined using the rmdev
command:
rmdev -l hdisk1
The definition of this physical volume will remain in the ODM. The -d flag
removes the definition from the ODM.
Note: The chpv command uses space in the /tmp directory to store
information while it is executing. If it fails, it could be due to lack of space in
the /tmp directory. Create more space in that directory and try again.
134 IBM ^ Certification Study Guide - pSeries AIX System Administration
6.3.5 Listing information about physical volumes
A physical volume correctly installed on the system can be assigned to a volume
group and can subsequently be used to hold file systems and logical volumes.
The information about free physical partitions and their availability within different
sectors on the disk can be very useful. The following section will discuss using
the lspv command to obtain such information as is pertinent to physical volumes.
Listing physical volumes on the system
The lspv command, run without any flags, will produce output that will identify
the physical volumes by name that are known to the system, as shown in the
following example:
# lspv
hdisk0 00615147ce54a7ee rootvg
hdisk1 00615147a877976a rootvg
#
The lsdev command with the -C option and -c class will also list the physical
volumes on the system along with the status of each physical volume, as shown
in the following example:
# lsdev -C -c disk
hdisk0 Available 40-58-00-0,0 16 Bit SCSI Disk Drive
hdisk1 Available 40-58-00-1,0 16 Bit SCSI Disk Drive
hdisk2 Available 20-68-L SSA Logical Disk Drive
hdisk3 Available 20-68-L SSA Logical Disk Drive
hdisk4 Available 20-68-L SSA Logical Disk Drive
hdisk5 Available 20-68-L SSA Logical Disk Drive
hdisk6 Available 20-68-L SSA Logical Disk Drive
Listing physical volume characteristics
The following example shows the use of the lspv command to retrieve more
detailed information about a physical volume:
# lspv hdisk1
PHYSICAL VOLUME: hdisk1 VOLUME GROUP: rootvg
PV IDENTIFIER: 00615147a877976a VG IDENTIFIER 00615147b27f2b40
PV STATE: active
STALE PARTITIONS: 0 ALLOCATABLE: yes
PP SIZE: 4 megabyte(s) LOGICAL VOLUMES: 13
TOTAL PPs: 238 (952 megabytes) VG DESCRIPTORS: 1
FREE PPs: 71 (284 megabytes)
USED PPs: 167 (668 megabytes)
FREE DISTRIBUTION: 48..02..00..00..21
USED DISTRIBUTION: 00..46..47..47..27
#
Chapter 6. Storage management, LVM, and file systems 135
The left hand pair of columns holds information about the physical volume itself.
The right hand pair displays information concerning the volume group of which
the physical volume is a member.
The following are the meanings of various fields in the preceding example.
PHYSICAL VOLUME The name of the specified physical volume.
PV IDENTIFIER The physical volume identifier (unique to the system).
PV STATE The state of the physical volume. This defines whether or
not the physical volume is available for logical
input/output operations. It can be changed using the
chpv command.
STALE PARTITIONS The number of stale partitions.
PP SIZE The size of a physical partition. This is a characteristic of
the volume group and is set only at the creation of the
volume group as an argument to the mkvg command.
The default size is 4 MB.
TOTAL PPs The total number of physical partitions including both
free and used partitions available on the physical
volume.
FREE PPs The number of free partitions available on the physical
volume.
USED PPs The number of used partitions on the physical volume.
FREE DISTRIBUTION This field summarizes the distribution, of free physical
partitions across the physical volume according to the
sections of the physical volume on which they reside.
USED DISTRIBUTION Same as free distribution except that it displays the
allocation of used physical partitions.
VOLUME GROUP The name of the volume group to which the physical
volume is allocated.
VG IDENTIFIER The numerical identifier of the volume group to which the
physical volume is allocated.
ALLOCATABLE Whether the system is permitted to allocate new physical
partitions on this physical volume.
LOGICAL VOLUMES The number of the logical volumes in the volume group.
VG DESCRIPTORS The number of VGDAs for this volume group that resides
on this particular physical volume.
136 IBM ^ Certification Study Guide - pSeries AIX System Administration
Listing logical volume allocation within a PV
The following example shows the lspv command with the -l option to list the
physical volume hdisk1. The output shows the names of all the logical volumes
on the physical volume, the number of physical and logical partitions allocated,
the distribution across the physical volume, and the mount point, if one exists:
# lspv -l hdisk1
hdisk1:
LV NAME LPs PPs DISTRIBUTION MOUNT POINT
rawlv 1 1 01..00..00..00..00 N/A
hd4 2 2 02..00..00..00..00 /
hd9var 1 1 01..00..00..00..00 /var
hd3 8 8 01..00..07..00..00 /tmp
lv06 5 5 00..05..00..00..00 /home2
lv07 13 13 00..13..00..00..00 /backfs
rawlv1 2 2 00..02..00..00..00 N/A
copied 2 2 00..02..00..00..00 N/A
newlv 1 1 00..01..00..00..00 N/A
fslv00 1 1 00..01..00..00..00 N/A
hd6 1 1 00..01..00..00..00 N/A
mytest 1 1 00..01..00..00..00 N/A
#
Listing physical partition allocation by PV region
The example provided in Figure 6-3 shows how to retrieve more detailed
information about the range of physical partitions allocated to a logical volume
and the region of disk used for those partitions.
Chapter 6. Storage management, LVM, and file systems 137
Figure 6-3 Status and characteristics of hdisk1 by physical partitions
The following is the description of the fields shown in Figure 6-3.
PP RANGE The range of physical partitions for which the current row of
data applies.
STATE Whether or not the partitions have been allocated. Value can
be either used or free.
REGION Region of the disk within which the partitions are located.
LV NAME Name of the logical volume to which the partitions in question
have been allocated.
TYPE Type of file system residing on the logical volume.
MOUNT POINT Mount point of the file system if applicable.
138 IBM ^ Certification Study Guide - pSeries AIX System Administration
Listing physical partition allocation table
To determine the degree of contiguity of data on the system to improve the I/O
performance of a logical volume, you can use the lspv command with the -M
option as shown in Figure 6-4. You may decide to reorganize the system after
analyzing the output.
Figure 6-4 Physical partition allocation by disk region
The first column indicates the physical partition (if a group of contiguous
partitions are free, it will indicate a range of partitions) for a particular hard disk.
The second column indicates which logical partition of which logical volume is
associated with that physical partition.
Migrating the contents of a physical volume
The physical partitions belonging to one or more specified logical volumes can
be moved from one physical volume to one or more other physical volumes within
a volume group using the migratepv command.
Chapter 6. Storage management, LVM, and file systems 139
Figure 6-5 migratepv does not work across volume groups
The following procedure describes how to move the data from a failing disk
before it is removed for repair or replacement:
1. Determine which disks are in the volume group. Make sure that the source
and destination physical volumes are in the same volume group. If the source
and destination physical volumes are in the same volume group, proceed to
step 3.
# lsvg -p rootvg
rootvg:
PV_NAME PV STATE TOTAL PPs FREE PPs FREE DISTRIBUTION
hdisk0 active 159 0 00..00..00..00..00
Note: The migratepv command cannot move data between different
volume groups, as shown in Figure 6-5. See Section 6.5.5, “Copying a
logical volume” on page 163 for examples on how to move data between
volume groups.
140 IBM ^ Certification Study Guide - pSeries AIX System Administration
2. If you are planning to migrate to a new disk, such as when you have a failing
disk, perform the following steps:
a. Make sure the disk is available by entering the following:
# lsdev -Cc disk
hdisk0 Available 00-08-00-30 670 MB SCSI Disk Drive
hdisk1 Available 00-08-00-20 857 MB SCSI Disk Drive
b. If the disk is listed and in the available state, make sure it does not belong
to another volume group using the following command. In the following
example, hdisk1 can be used as a destination disk:
# lspv
hdisk0 0000078752249812 rootvg
hdisk1 000000234ac56e9e none
c. If the disk is not listed or is not available, you need to check or install the
disk.
d. Add the new disk to the volume group using the command:
extendvg VGName hdiskNumber
3. Make sure that you have enough room on the target disk for the source that
you want to move.
a. Determine the number of physical partitions on the source disk by using
the following command. SourceDiskNumber will be of the form
hdiskNumber:
lspv SourceDiskNumber | grep "USED PPs"
The output will look similar to the following:
USED PPs: 159 (636 megabytes)
In this example, you would need 159 free PPs on the destination disk to
successfully complete the migration.
b. Determine the number of free physical partitions on the destination disk or
disks using the following command for each destination disk
(DestinationDiskNumber will be of the form hdiskNumber).
lspv DestinationDiskNumber | grep "FREE PPs"
Add the free PPs from all of the destination disks. If the sum is larger than
the number of USED PPs from step 3a, you will have enough space for the
migration.
4. Follow this step only if you are migrating data from a disk in the rootvg volume
group. If you are migrating data from a disk in a user-defined volume group,
proceed to step 5.
Check to see if the boot logical volume (hd5) is on the source disk:
lspv -l SourceDiskNumber | grep hd5
Chapter 6. Storage management, LVM, and file systems 141
If you get no output, the boot logical volume is not located on the source disk.
Continue to step 5.
If you get output similar to the following:
hd5 2 2 02..00..00..00..00 /blv
then run the following command:
migratepv -l hd5 SourceDiskNumber DestinationDiskNumber
Next, you will get a message warning you to perform the bosboot command
on the destination disk.
Run the mkboot -c command to clear the boot record on the source. Do the
following on pre-AIX Version 4.2 systems:
bosboot -a -d /dev/DestinationDiskNumber
then:
bootlist -m normal DestinationDiskNumber
then:
mkboot -c -d /dev/SourceDiskNumber
5. Executing the SMIT fast path command smitty migratepv to migrate the data
will show a screen similar to Figure 6-6 on page 142.
Note:
The migratepv command is not allowed if the volume group is varied on
in a concurrent mode.
You must either have root user authority or be a member of the
system group to run the migratepv command.
Note: When the boot logical volume is migrated from a physical volume,
the boot record on the source should be cleared. Failure to clear this
record may result in a system hang. When you run the bosboot
command, you must also run: mkboot -c
142 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 6-6 smitty migratepv command
6. List the physical volumes by pressing F4, and select the source physical
volume you examined previously.
7. Go to the DESTINATION physical volume field. If you accept the default, all
the physical volumes in the volume group are available for the transfer.
Otherwise, select one or more disks with adequate space for the partitions
you will be moving (from step 4).
8. If you wish, go to the Move only data belonging to this LOGICAL VOLUME
field and list and select a logical volume. You will move only the physical
partitions allocated to the logical volume specified that are located on the
physical volume selected as the source physical volume.
9. Press Enter to move the physical partitions.
10.To remove the source disk from the volume group, such as when it is failing,
enter the following command:
reducevg VGNname SourceDiskNumber
11.Before physically removing the source disk from the system, such as when it
is failing, enter the following command:
rmdev -l SourceDiskNumber -d
Chapter 6. Storage management, LVM, and file systems 143
The following are additional examples of using the migratepv command:
Use the following command to move physical partitions from hdisk1 to hdisk6
and hdisk7 (all physical volumes are in one volume group):
migratepv hdisk1 hdisk6 hdisk7
Use the following command to move physical partitions in logical volume lv02
from hdisk1 to hdisk6:
migratepv -l lv02 hdisk1 hdisk6
6.4 Managing volume groups
This section discusses the functions that can be performed on volume groups. As
with physical volumes, volume groups can be created and removed, and their
characteristics can be modified. Additional functions, such as activating and
deactivating volume groups, can also be performed.
6.4.1 Listing volume group characteristics
The volume group charateristics are provided by the lsvg command.
# lsvg rootvg
VOLUME GROUP: rootvg VG IDENTIFIER: 00015f8f00004c00000000f52c7c20de
VG STATE: active PP SIZE: 16 megabyte(s)
VG PERMISSION: read/write TOTAL PPs: 1084 (17344 megabytes)
MAX LVs: 256 FREE PPs: 996 (15936 megabytes)
LVs: 10 USED PPs: 88 (1408 megabytes)
OPEN LVs: 9 QUORUM: 2
TOTAL PVs: 2 VG DESCRIPTORS: 3
STALE PVs: 0 STALE PPs: 0
ACTIVE PVs: 2 AUTO ON: yes
MAX PPs per PV: 1016 MAX PVs: 32
LTG size: 128 kilobyte(s) AUTO SYNC: no
HOT SPARE: no BB POLICY: relocatable
The following describes the fields shown in the previous example.
Volume group Name of the volume group. Volume group names must be
unique systemwide and can range from 1 to 15
characters.
Volume group state State of the volume group. If the volume group is
activated with the varyonvg command, the state is either
active/complete (indicating all physical volumes are
active) or active/partial (indicating some physical volumes
are not active). If the volume group is not activated with
the varyonvg command, the state is inactive.
Permission Access permission: read-only or read-write.
144 IBM ^ Certification Study Guide - pSeries AIX System Administration
Max LVs Maximum number of logical volumes allowed in the
volume group. LVs Number of logical volumes currently
in the volume group.
Open LVs Number of logical volumes within the volume group that
are currently open.
Total PVs Total number of physical volumes within the volume
group.
Active PVs Number of physical volumes that are currently active.
VG identifier The volume group identifier.
PP size Size of each physical partition.
Total PPs Total number of physical partitions within the volume
group.
Free PPs Number of physical partitions not allocated.
Alloc PPs Number of physical partitions currently allocated to logical
volumes. Quorum Number of physical volumes needed
for a majority.
VGDS Number of volume group descriptor areas within the
volume group.
Auto-on Automatic activation at IPL (yes or no).
Concurrent States whether the volume group is Concurrent Capable
or Non-Concurrent Capable.
Auto-Concurrent States whether you should autovary the Concurrent
Capable volume group in concurrent or non-concurrent
mode. For volume groups that are Non-Concurrent
Capable, this value defaults to Disabled.
VG Mode The vary on mode of the volume group: Concurrent or
Non-Concurrent.
Node ID Node id of this node if volume group is varied on in
concurrent node. Active Nodes Node ids of other
concurrent nodes that have this volume group varied on.
Max PPs Per PV Maximum number of physical partitions per physical
volume allowed for this volume group.
Max PVs Maximum number of physical volumes allowed in this
volume group.
LTG size Logical track group size, in number of kilobytes, of the
volume group.
BB POLICY Bad block relocation policy of the volume group.
Chapter 6. Storage management, LVM, and file systems 145
SNAPSHOT VG Snapshot volume group name if the snapshot volume
group is active else snapshot volume group identifier.
PRIMARY VG Original volume group name of a snapshot volume group
if the original volume group is active else original volume
group identifier.
6.4.2 Adding a volume group
Before a new volume group can be added to the system, one or more physical
volumes not used in other volume groups, and in an available state, must exist
on the system.
It is important to decide upon certain information, such as the volume group
name and the physical volumes to use, prior to adding a volume group.
New volume groups can be added to the system by using the mkvg command or
by using SMIT. Of all the characteristics set at creation time of the volume group,
the following are the most important:
The volume group names must be unique on the system.
The names of all physical volumes to be used in the new volume group.
The maximum number of physical volumes that can exist in the volume
group.
The physical partition size for the volume group.
The flag to activate the volume group automatically at each system restart.
The following example shows the use of the mkvg command to create a volume
group, myvg, using the physical volumes hdisk1 and hdisk5, with a physical
partition size of 4 KB. The volume group is limited to a maximum of 10 physical
volumes.
mkvg -y myvg -d 10 -s 8 hdisk1 hdisk5
Alternatively, you can use the SMIT fast path command smitty mkvg to obtain the
screen shown in Figure 6-7 and enter the characteristics of the volume group to
be created in the fields.
146 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 6-7 smitty mkvg command
The smitty mkvg command will automatically activate the volume group by
calling the varyonvg command. Moreover, the SMIT command limits the following
functions, as compared to executing from the command line:
smitty mkvg does not provide the -d flag to set the maximum number of
physical volumes. It uses a default value of 32.
smitty mkvg does not provide the -m flag to set the maximum size of the
physical volume. This flag will determine how many physical partitions are
used. It uses a set value of 1016 partitions.
smitty mkvg always uses the -f flag to force the creation of the volume group.
6.4.3 Modifying volume group characteristics
The following sections discuss the tasks required to modify a volume group’s
characteristics.
Note: For a new volume group to be successfully added to the system
using the mkvg command, the root file system should have about 2 MB of
free space. Check this using the df command. This free space is required
because a file is written in the directory /etc/vg each time a new volume
group is added.
Chapter 6. Storage management, LVM, and file systems 147
Modifying volume group activation characteristics
The following command allows the volume group, newvg, to be varied on
automatically each time a system is restarted:
chvg -ay newvg
The following command will turn off the automatic varying on of the volume
group, newvg, at the system restart:
chvg -an newvg
Unlocking a volume group
A volume group can become locked when an LVM command terminates
abnormally, due to a system crash while an LVM operation was being performed
on the system.
In AIX Version 4 and later, it is also possible to unlock a volume group. The
following example shows the command to unlock the newvg volume group.
chvg -u newvg
Adding a physical volume
It may be necessary to increase the free space available in a volume group, so
that existing file systems and logical volumes within the volume group can be
extended, or new ones can be added. This requires additional physical volumes
be made available within the volume group.
It is possible to add physical volumes to a volume group up to the maximum
specified at creation time. A physical volume can be added using the extendvg
command. The following example shows the command to add the physical
volume hdisk3 to volume group newvg.
extendvg newvg hdisk3
Alternatively, you can use the SMIT fast path command smitty vgsc and select
Add a Physical Volume to a Volume Group.
Note: The extendvg command will fail if the physical volume being added
already belongs to a varied on volume group on the current system. Also, if
the physical volume being added belongs to a volume group that is
currently not varied on, the user will be asked to confirm whether or not to
continue.
148 IBM ^ Certification Study Guide - pSeries AIX System Administration
Removing a physical volume
The volume group must be varied on before it can be reduced. The following
example shows how to remove the physical volume, hdisk3, from the volume
group, myvg.
reducevg myvg hdisk3
Alternatively, you can use the SMIT fast path command smitty reducevg to
remove a physical volume from a volume group.
If the logical volumes on the physical volume specified to be removed also span
other physical volumes in the volume group, the removal operation may destroy
the integrity of those logical volumes regardless of the physical volume on which
they reside.
When you remove all physical volumes in a volume group, the volume group itself
is also removed.
Removing a physical volume reference
Sometimes a disk is removed from the system without first running reducevg
VolumeGroup PhysicalVolume. The VGDA still has the removed disk’s reference,
but the physical volume name no longer exists or has been reassigned. To
remove references to the disk that has been removed, you can still use the
reducevg command using the PVID of the physical volume removed. The
following command will remove the reference of a physical volume (with PVID of
000005265ac63976) from the volume group newvg.
reducevg VolumeGroup 000005265ac63976
6.4.4 Importing and exporting a volume group
There may be times when a volume group needs to be moved from one RS/6000
or ^ pSeries system to another, so that logical volume and file system
data in the volume group can be accessed directly on the target system.
Note: The reducevg command provides the -d and -f flags.
The -d flag can be dangerous because it automatically deletes all logical
volume data on the physical volume before removing the physical volume
from the volume group. If a logical volume spans multiple physical volumes,
the removal of any of those physical volumes may jeopardize the integrity
of the entire logical volume.
The -f flag makes the -d flag even more dangerous by suppressing
interaction with a user requesting confirmation that the logical volume
should be deleted.
Chapter 6. Storage management, LVM, and file systems 149
To remove the system definition of a volume group from the ODM database, the
volume group needs to be exported using the exportvg command. This
command will not remove any user data in the volume group, but will only
remove its definition from the ODM database.
Similarly, when a volume group is moved, the target system needs to add the
definition of the new volume group. This can be achieved by importing the
volume group by using the importvg command, which will add an entry to the
ODM database.
The following example shows the export of the volume group myvg.
exportvg myvg
And, the following example shows the import of the volume group myvg.
importvg -y myvg hdisk12
You can also use the SMIT fast path commands, smitty exportvg or smitty
importvg, to export or import a volume group.
If the specified volume group name is already in use, the importvg command will
fail with an appropriate error message since duplicate volume group names are
not allowed. In this instance, the command can be rerun with a unique volume
group name specified. The command can also be rerun without the -y flag or the
volume group name, which gives the imported volume group a unique system
default name.
It is also possible that some logical volume names may also conflict with those
already on the system. The importvg command will automatically reassign these
with system default names. The important thing to remember when moving
volume groups from system to system is that the exportvg command is always
run on the source system prior to importing the volume group to the target
system.
Consider that a volume group is imported on system Y without actually
performing an exportvg on system X. If system Y makes a change to the volume
group, such as removing a physical volume from the volume group, and the
volume group is imported back onto system X, the ODM database on system X
will not be consistent with the changed information for this volume group.
However, it is worth noting that a volume group can be moved to another system
without first being exported on the source system.
150 IBM ^ Certification Study Guide - pSeries AIX System Administration
You can also use exportvg and importvg to change the name of a user-defined
volume group, as shown in the following example:
# lspv
hdisk0 006151409772fa27 rootvg
hdisk1 00382642e0e14dbd vg00
# varyoffvg vg00
# exportvg vg00
# importvg -y cadsvg hdisk1
cadsvg
# lspv
hdisk0 006151409772fa27 rootvg
hdisk1 00382642e0e14dbd cadsvg
Note:
The importvg command changes the name of an imported logical volume
if there currently is a logical volume with the same name already on the
system. An error message is printed to standard error if an imported logical
volume is renamed. The importvg command also creates file mount points
and entries in /etc/filesystems, if possible (if there are no conflicts).
A volume group that has a paging space volume on it cannot be exported
while the paging space is active. Before exporting a volume group with an
active paging space, ensure that the paging space is not activated
automatically at system initialization by running the following command:
chps -a n paging_space_name
Then, reboot the system so that the paging space is inactive. AIX 5L
Version 5.1 enhances paging space deactivation. See “Deactivating paging
spaces” on page 204 for more information.
If you do not activate the volume group through smitty importvg, you must
run the varyonvg command to enable access to the file systems and logical
volumes.
If you imported a volume group that contains file systems, or if you
activated the volume group through smitty importvg, it is highly
recommended that you run the fsck command before you mount the file
systems. If you are moving the volume group to another system, be sure to
unconfigure the disks before moving them.
The smitty exportvg command deletes references to file systems in
/etc/filesystems, but it leaves the mount points on the system.
Chapter 6. Storage management, LVM, and file systems 151
6.4.5 Varying on and varying off a volume group
Once a volume group exists, it can be made available for use for system
administrative activities using the varyonvg command. This process involves the
following steps:
1. Each VGDA on each physical volume in a volume group is read.
2. The header and trailer time stamps within each VGDA are read. These time
stamps must match for a VGDA to be valid.
3. If a majority of VGDAs (called the quorum) are valid, then the vary on process
proceeds. If they are not, then the vary on fails.
4. The system will take the most recent VGDA (the one with the latest time
stamp) and write it over all other VGDAs so they all match.
5. The syncvg command is run to resynchronize any stale partition present (in
the case where mirroring is in use).
The varyonvg command has the following options that can be used to overcome
damage to the volume group structure or give status information:
The -f flag can be used to force a volume group to be varied on even when
inconsistencies are detected. These inconsistencies are generally differences
between the configuration data for each volume group held in the ODM
database and VGDA.
The -n flag will suppress the invocation of the syncvg command at vary on
time. When a volume group is varied on, and stale partitions are detected, the
vary on process will invoke the syncvg command to synchronize the stale
partitions. This option is of value when you wish to carefully recover a volume
group and you want to ensure that you do not accidentally write bad mirrored
copies of data over good copies.
The -s flag allows a volume group to be varied on in the maintenance or
system management modes. Logical volume commands can operate on the
volume group, but no logical volume can be opened for input or output.
The following example shows the command to activate the volume group newvg.
varyonvg newvg
You can also use the SMIT fast path command, smitty varyonvg, to obtain
output similar to what is presented in Figure 6-8 on page 152. Enter the name of
the volume group to be varied on, along with all the options.
152 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 6-8 smitty varyonvg command
The varyoffvg command will deactivate a volume group and its associated
logical volumes. This requires that the logical volumes be closed, which requires
that file systems associated with logical volumes be unmounted. The varyoffvg
command also allows the use of the -s flag to change the volume group from
being active to being in the maintenance or systems management mode.
The following example shows the command to deactivate the volume group
myvg.
varyoffvg myvg
You can also use the SMIT fast path command, smitty varyoffvg, which will
show a screen is similar to that shown in Figure 6-9 on page 153. You can enter
the name of the volume group to be varied off, and you can also put the volume
group into system management mode.
Note: In AIX Version 4 and later, when a volume group is imported, it is
automatically varied on; while in AIX Version 3, the volume group has to be
varied on separately.
Chapter 6. Storage management, LVM, and file systems 153
Figure 6-9 smitty varyoffvg command
6.4.6 Monitoring volume groups
The lsvg command interrogates the ODM database for all volume groups
currently known to the system. The following are a few examples showing the
use of the lsvg command to monitor volume groups.
Listing the volume groups
The following example shows the use of the lsvg command without any flag to
list all the volume groups known to the system:
# lsvg
rootvg
altinst_rootvg
datavg
testvg
#
The following example shows how to list the volume groups that are currently
active (varied on):
# lsvg -o
testvg
datavg
rootvg
154 IBM ^ Certification Study Guide - pSeries AIX System Administration
Listing the characteristics of a volume group
The example in Figure 6-10 shows the command used to list detailed information
and status about the volume group’s characteristics.
Figure 6-10 lsvg rootvg command
Listing the logical volumes in a volume group
The example in Figure 6-11 shows the command used to display the names,
characteristics, and status of all the logical volumes in the volume group rootvg.
Figure 6-11 lsvg -l rootvg command
Chapter 6. Storage management, LVM, and file systems 155
List the physical volume status within a volume group
The example shown in Figure 6-12 shows the use of the lsvg command with the
-p flag to display a list of physical volumes contained in a volume group, as well
as some status information including physical partition allocation. This form of
the lsvg command is useful for summarizing the concentrations of free space on
the system.
Figure 6-12 lsvg -p vgname command
The following is the description of the various fields shown in Figure 6-12.
PV_NAME The name of the physical volume.
PV STATE Whether or not this physical volume is active.
TOTAL PPs The total number of physical partitions on this physical
volume.
FREE PPs The total number of unused physical partitions on this
physical volume.
FREE DISTRIBUTION The location of the free physical partitions on the
physical volumes. There are five columns, one for each
disk region, in the following order: Outside edge, Outside
middle, Center, Inside middle, Inside edge.
6.4.7 Reorganizing a volume group
The reorgvg command is used to reorganize the physical partition allocation for
a volume group according to the allocation characteristics of each logical
volume.
The following is the syntax of the reorgvg command:
reorgvg [ -i ] VolumeGroup [ LogicalVolume ... ]
The volume group must be varied on and must have free partitions before you
can use the reorgvg command. The relocatable flag of each logical volume must
be set to y using the chlv -r command for the reorganization to take effect;
otherwise, the logical volume is ignored.
156 IBM ^ Certification Study Guide - pSeries AIX System Administration
You can also use the SMIT fast path command, smitty reorgvg, to do the same
task.
See Table 6-2 for details on a flag for the reorgvg command.
Table 6-2 reorgvg command flags
Examples of reorganizing volume groups are as follows:
The following command reorganizes the logical volumes lv03, lv04, and lv07
on volume group vg02:
reorgvg vg02 lv03 lv04 lv07
Only the listed logical volumes are reorganized on vg02.
The following example shows how to reorganize the partitions located on
physical volumes hdisk04 and hdisk06 that belong to the logical volumes
lv203 and lv205:
echo "hdisk04 hdisk06" | reorgvg -i vg02 lv203 lv205
Only the partitions located on physical volumes hdisk04 and hdisk06 of
volume group vg02, which belong to the logical volumes lv203 and lv205, are
reorganized.
Note:
1. The reorgvg command does not reorganize the placement of allocated
physical partitions for striped logical volumes.
2. At least one free physical partition must exist on the specified volume
group for the reorgvg command to run successfully.
3. In AIX Version 4.2, or later, if you enter the reorgvg command with the
volume group name and no other arguments, it will only reorganize the
first logical volume in the volume group. The first logical volume is the
one listed by the lsvg -l VolumeName command.
Flag Description
-i Specifies physical volume names read from standard input. Only the
partitions on these physical volumes are organized.
Chapter 6. Storage management, LVM, and file systems 157
6.4.8 Synchronizing a volume group
The syncvg command is used to synchronize logical volume copies that are not
current (stale).
The following is the syntax of syncvg command:
syncvg [ -f ] [ -i ] [ -H ] [ -P NumParallelLps ] { -l | -p | -v }
Name ...
The syncvg command synchronizes the physical partitions, which are copies of
the original physical partition that are not current. The syncvg command can be
used with logical volumes, physical volumes, or volume groups, with the Name
parameter representing the logical volume name, physical volume name, or
volume group name. The synchronization process can be time consuming
depending on the hardware characteristics and the amount of data.
When the -f flag is used, an uncorrupted physical copy is chosen and propagated
to all other copies of the logical partition whether or not they are stale.
Unless disabled, the copies within a volume group are synchronized
automatically when the volume group is activated by the varyonvg command.
The commonly used flags with the syncvg command are shown in Table 6-3.
Table 6-3 Key flags for the syncvg command
The following examples show the use of the syncvg command:
To synchronize the copies on physical volumes hdisk04 and hdisk05, run the
following command:
syncvg -p hdisk04 hdisk05
To synchronize the copies on volume groups vg04 and vg05, run the following
command:
syncvg -v vg04 vg05
Flag Description
-p Specifies that the Name parameter represents a physical volume
device name.
-v Specifies that the Name parameter represents a volume group device
name.
158 IBM ^ Certification Study Guide - pSeries AIX System Administration
6.5 Managing logical volumes
Physical volumes and volume groups are normally not addressed directly by
users and applications to access data, and they cannot be manipulated to
provide disk space for use by users and applications. However, logical volumes
provide the mechanism to make disk space available for use, giving users and
applications the ability to access data stored on them.
When you create a logical volume, you specify the number of logical partitions for
the logical volume. A logical partition maps to one, two, or three physical
partitions, depending on the number of copies of your data you want to maintain.
For example, you can specify a logical volume to be mirrored and have more than
one copy as shown in Figure 6-13. One copy of the logical volume (the default)
indicates that there is a direct mapping of one logical partition to one physical
partition.
Figure 6-13 Mapping of LP to PP for mirrored and non-mirrored data
The management of logical volumes is, therefore, the management of disk space
that is available for use. This section will review the functions that can be
performed by users on logical volumes.
Chapter 6. Storage management, LVM, and file systems 159
6.5.1 Adding a logical volume
You can create additional logical volumes with the mklv command. This
command allows you to specify the name of the logical volume and define its
characteristics including the number of the logical partitions to allocate for it. The
default maximum size for a logical volume at creation is 128 logical partitions.
Creating a logical volume using the command line
The mklv command is used to create a new logical volume. The following is the
syntax of the mklv command, and the most commonly used flags are shown in
Tabl e 6-4.
mklv [ -a Position ] [ -b BadBlocks ] [ -c Copies ] [ -d Schedule ]
[ -e Range ] [ -i ] [ -L Label ] [ -m MapFile ] [ -r Relocate ] [ -s Strict ]
[ -t Typ e ] [ -u UpperBound ] [ -v Verify ] [ -w MirrorWriteConsistency ]
[ -x Maximum ] [ -y NewLogicalVolume | -Y Prefix ] [ -S StripeSize ]
[ -U Userid ] [ -G Groupid ] [-P Modes ] VolumeGroup Number
[ PhysicalVolume ... ]
Table 6-4 mklv command flags
Flag Description
-c copies Sets the number of physical partitions allocated for each logical
partition. The copies variable can be set to a value from 1 to 3; the
default is 1.
-i Reads the PhysicalVolume parameter from standard input. Use the -i
flag only when PhysicalVolume is entered through standard input.
-L Sets the logical volume label. The default label is None. The
maximum size of the label file is 127 characters. If the logical volume
is going to be used as a journaled file system (JFS), then the JFS will
use this field to store the mount point of the file system on that logical
volume for future reference.
-P Modes Specifies permissions (file modes) for the logical volume special file.
-t Type Sets the logical volume type. The standard types are JFS (file
systems), JFSLOG (journal file system logs), and paging (paging
spaces), but a user can define other logical volume types with this
flag. You cannot create a logical volume of type boot. The default is
JFS. If a log is manually created for a file system, the user must run
the logform command to clean out the new JFSLOG before the log
can be used. Use the following command to format the logical volume
logdev:
logform /dev/logdev
where /dev/logdev is the absolute path to the logical volume.
160 IBM ^ Certification Study Guide - pSeries AIX System Administration
The following example shows the use of mklv command to create a new logical
volume, newlv. This will create a logical volume called newlv in the rootvg, and it
will have 10 logical partitions, and each logical partition consists of two physical
partitions.
mklv -y newlv -c 2 rootvg 10
Creating a logical volume using SMIT
You can use the following SMIT dialog to create a logical volume.
1. Run the command smitty mklv
2. Press F4 to get a list of all the volume groups that are defined in the system. A
screen similar to Figure 6-14 will be shown:
Figure 6-14 Selecting the volume group to hold the new logical volume
-y NewLV Specifies the logical volume name to use instead of using a system-
generated name. Logical volume names must be unique names
system-wide and can range from 1 to 15 characters. If the volume
group is varied on in concurrent mode, the new name should be
unique across all the concurrent nodes the volume group is varied on.
The name cannot begin with a prefix already defined in the PdDv
class in the Device Configuration Database for other devices.
Flag Description
Chapter 6. Storage management, LVM, and file systems 161
3. Use the arrow keys to select the volume group in which you want to create
your new logical volume and press Enter. A screen similar to Figure 6-15 will
be shown.
Figure 6-15 Setting characteristics of the new logical volume
4. In the Logical volume NAME field, enter the name of the logical volume you
are creating (newlv, in this case).
5. In the Number of LOGICAL PARTITIONS field, enter the number of logical
partitions you want to assign to your new logical volume (10, in this case).
Each logical partition corresponds to one or more physical partitions
depending upon the number of copies of data you want to keep.
6. In the PHYSICAL VOLUME names field, enter the physical volumes that you
want to use for this logical volume. If you do not specify any names, the first
PV in the system will be used to place all the data on.
7. In the Number of COPIES of each logical partition field, enter the number of
LP copies that you want for your data. A value of 1 to 3 is allowed.
8. Press Enter to create the logical volume.
6.5.2 Removing a logical volume
You may need to remove a logical volume if it is no longer in use for storage
purposes by users and applications. The rmlv command can be used to remove
a logical volume.
162 IBM ^ Certification Study Guide - pSeries AIX System Administration
Removing a logical volume using the command line
The rmlv command is used to remove a logical volume. The following shows the
general syntax of the command, and its commonly used flags are shown in
Tabl e 6-5.
rmlv [ -f ] [ -p PhysicalVolume ] LogicalVolume ...
Table 6-5 rmlv command flags
The following shows the command to remove a logical volume, newlv:
# rmlv newlv
Warning, all data on logical volume newlv will be destroyed.
rmlv: Do you wish to continue? y(es) n(o) y
#
Entering a y as the response to this dialogue and pressing Enter will complete
the process of deletion of a logical volume.
Removing a logical volume using SMIT
Alternatively, you can use the SMIT fast path command smitty rmlv to remove a
logical volume.
6.5.3 Reducing the size of a logical volume
The following steps can be performed to reduce the size of a logical volume to
free up excess logical partition allocation:
1. Back up all data in the logical volume.
2. Remove the logical volume.
3. Recreate the logical volume with the reduced logical partition allocation.
4. Restore the data.
The resulting free space could be put to better use by allocating it to other logical
volumes requiring it.
Flag Description
-f Removes the logical volumes without requesting confirmation.
-p PhysicalVolume Removes only the logical partition on the PhysicalVolume. The
logical volume is not removed unless there are no other physical
partitions allocated.
Chapter 6. Storage management, LVM, and file systems 163
6.5.4 Increasing the size of a logical volume
An existing logical volume can be increased in size by using the extendlv
command or SMIT.
If the logical volume is used by a journaled file system, you can also use the chfs
command or the SMIT fast path command smitty chjfs to increase the size of
the logical volume.
Extending a logical volume using the command line
The extendlv command is used to increase the size of a logical volume. The
following is the general syntax of the command and its commonly used flags:
extendlv [ -a Position ] [ -e Range ] [ -u Upperbound ] [ -s Strict ]
LogicalVolume Partitions [ PhysicalVolume ... ]
The following example shows the use of the extendlv command to add three
more logical partitions to the logical volume you created:
extendlv newlv 3
Extending a Logical Volume Using SMIT
The SMIT fast path smitty extendlv command can be used to increase the size
of a logical volume.
6.5.5 Copying a logical volume
Logical volumes may need to be copied for a number of reasons. If a disk is to be
removed and replaced with a new disk, the logical volumes on that disk will need
to be copied to the new disk. Logical volumes can be copied to new logical
volumes or to existing logical volumes that are then overwritten.
Copying a logical volume using the command line
The following example shows the use of the cplv command to copy a logical
volume:
cplv -v myvg -y newlv oldlv
This copies the contents of oldlv to a new logical volume, called newlv, in the
volume group myvg. If the volume group is not specified, the new logical volume
will be created in the same volume group as the old logical volume. This
command creates a new logical volume.
The following example demonstrates how to copy a logical volume to an existing
logical volume:
cplv -e existinglv oldlv
164 IBM ^ Certification Study Guide - pSeries AIX System Administration
This copies the contents of oldlv to the logical volume existinglv in the same
volume group. Confirmation for the copy will be requested, since all data in
existinglv will be overwritten.
If existinglv is smaller than oldlv, then data will be lost probably resulting in
corruption.
Copying a logical volume using SMIT
Alternatively, you can use the SMIT fast path command, smitty cplv, to obtain a
screen similar to that shown in Figure 6-16.
Figure 6-16 smitty cplv command
1. Select Copy over an existing logical volume. A screen similar to Figure 6-17
will be shown.
Note: Do not copy from a larger logical volume containing data to a smaller
one. Doing so results in a corrupted file system, because some data is not
copied. This command will fail if the cplv creates a new logical volume,
and the volume group is varied on in concurrent mode.
Chapter 6. Storage management, LVM, and file systems 165
Figure 6-17 Selecting source and destination logical volumes
2. Enter the name of the logical volume you want to copy in the SOURCE logical
volume name field.
3. Enter the name of the logical volume on which you want to copy your existing
logical volume onto in the DESTINATION logical volume name field. This
name can be of an existing logical volume that you have already created, or it
can be a new logical volume that you want to create. Press Enter to complete
this step.
Note: You might encounter the following error:
cplv : Destination logical volume must have type set to copy
If this is the case, use the following command:
chlv -t copy Destination_Logical_Volume_Name
Return to your SMIT session. Now the system will allow you to copy the
logical volume. This has been done to ensure extra security so that you do
not overwrite your data accidently.
166 IBM ^ Certification Study Guide - pSeries AIX System Administration
6.5.6 Splitting copies of a logical volume
The splitlvcopy command splits copies from one logical volume and creates a
new and separate logical volume from them. The general syntax of the
splitlvcopy command is as follows:
splitlvcopy [ -f ] [ -y NewLogicalVolumeName ] [ -Y Prefix ] LogicalVolume
Copies [ PhysicalVolume ... ]
To split one copy of each logical partition belonging to the logical volume named
oldlv which currently has 3 copies of each logical partition, and create the logical
volume newlv, use the splitlvcopy command as follows:
splitlvcopy -y newlv oldlv 2
Each logical partition in the logical volume oldlv now has two physical partitions.
Each logical partition in the logical volume newlv now has one physical partition.
6.5.7 Listing logical volumes
The following logical volumes are automatically created at system installation
time:
hd5 This is the boot logical volume that holds the boot code. It is available
only at system startup time.
hd6 This is the default paging space logical volume that is used by the
system to perform paging.
hd8 This logical volume is used as the default logging space for the
journaled file systems.
hd4 This logical volume in used by the /, root file system.
hd2 This logical volume is used by the /usr file system.
hd9var This logical volume is used by the /var file system.
hd3 This logical volume used by the /tmp file system.
hd1 This logical volume is used by the /home file system.
Note: Although the splitlvcopy command can split logical volumes that are
open, including logical volumes containing mounted file systems, this is not
recommended. You may lose consistency between LogicalVolume and
NewLogicalVolume if the logical volume is accessed by multiple processes
simultaneously. When splitting an open logical volume, you implicitly accept
the risk of potential data loss and data corruption associated with this action.
To avoid the potential corruption window, unmount file systems and close
logical volumes before splitting them.
Chapter 6. Storage management, LVM, and file systems 167
The following command will list all the logical volumes defined on the system, as
shown in Figure 6-18:
lsvg | lsvg -il
Figure 6-18 Logical volume listing
The lslv command can be used to view all the attributes related to a logical
volume (newlv) as shown in Figure 6-19 on page 168.,
168 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 6-19 Logical volume attributes
6.5.8 Logical volume size
The size of a logical volume is the space that is allocated to the logical volume
and is a factor of the number of logical partitions that are allocated to the logical
volume and the number of copies that you have told the system to maintain.
Therefore, the total space taken up by the logical volume is determined by the
following formula:
Total LV size=PP size * LPs assigned to LV * Number of copies of the LV
The following example shows how to calculate the logical volume size.
If PP size is 4 MB, LPs assigned to the logical volume are 10, and the number of
copies of the logical volume are 2, then the total space that will be allocated to
this logical volume will be 80 MB (4*10*2).
Chapter 6. Storage management, LVM, and file systems 169
6.6 Managing journaled file systems
A file system is a set of files, directories, and other structures. File systems
maintain information and identify the location of a file or directory's data. In
addition to files and directories, file systems may contain a boot block, a
superblock, bitmaps, and one or more allocation groups. An allocation group
contains disk i-nodes and fragments.
The following three types of file systems are supported on an AIX system:
Journaled File System This native file system type is called the journaled file
system (JFS). Each journaled file system resides on a
separate logical volume. The operating system mounts
some journaled file systems during initialization (those
that are required to boot and run the system) and
mounts others at that time only if directed to do so in
/etc/filesystems.
Network File System The network file system (NFS) is a distributed file
system that allows users to access files and directories
located on remote computers and use those files and
directories as though they are local.
CD-ROM File System The CD-ROM file system (CDRFS) is a file system
type that allows you to access the contents of a
CD-ROM through the normal file system interfaces.
The Journaled File System (JFS) divides the logical volume into a number of
fixed size units called logical blocks. The logical blocks in the file system are
organized as follows:
Logical Block 0 The first logical block in the file system is reserved and
available for a bootstrap program or any other required
information; this block is unused by the file system.
Superblock The first and thirty-first logical blocks are reserved for the
superblock (logical block 31 being a backup copy). The
super block contains information, such as the overall size
of the file system in 512 byte blocks, the file system name,
file system log device address (logs will be covered later
in this section), version number, and the file system state.
Allocation Groups The rest of the logical blocks in the file system are divided
into a number of allocation groups. An allocation group
consists of data blocks and i-nodes to reference those
data blocks when they are allocated to directories or files.
These groups can be used to tailor the physical
placement of data on a disk.
170 IBM ^ Certification Study Guide - pSeries AIX System Administration
6.6.1 Characteristics of the journaled file system
The size for a Journaled File System (JFS) is defined when the file system is
created considering the following parameters:
Number of i-nodes
Allocation group size
File system fragment addressability
Journaled File System log size
Maximum Journaled File System size
Number of i-nodes
The total number of i-nodes in a file system limits the total number of files and the
total size of the file system. The JFS provides the nbpi (number of bytes per
i-node) parameter that affects the number of i-nodes in a file system. JFS
supports nbpi values of 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, and
131072. The values 32768, 65536, and 131072 only apply to AIX Version 4.2 or
later.
For example, to create an 8 MB file system with an nbpi value of 4096, an i-node
will be generated for each 4096 bytes of data. This would result in a maximum of
2048 i-nodes for an 8 MB file system, which means that if every file in the file
system is ideally 4 KB in length, a maximum of 2048 files can be created in the
file system.
The JFS restricts all file systems to 16 MB (2
24
) i-nodes.
Allocation group size
AIX Version 4.2 and later supports various allocation group sizes. The JFS
segregates file system space into groupings of i-nodes and disk blocks for user
data. These groupings are called allocation groups. The allocation group size
can be specified when the file system is created. The allocation group sizes are 8
MB, 16 MB, 32 MB, and 64 MB. Each allocation group size has an associated
nbpi range. The ranges are defined in Table 6-6.
Table 6-6 Allowable nbpi values
Allocation Group size in MB Maximum number of i-nodes
8 512, 1024, 2048, 4096, 8192, and 16384
16 1024, 2048, 4096, 8192, 16384, and 32768
32 2048, 4096, 8192, 16384, 32768, and 65536
64 4096, 8192, 16384, 32768, 65536, and 131072
Chapter 6. Storage management, LVM, and file systems 171
File system fragment addressability
The JFS supports four fragment sizes: 512, 1024, 2048, and 4096 byte units of
contiguous disk space. The JFS maintains fragment addresses in i-nodes and
indirect blocks as 28-bit numbers. Each fragment must be addressable by a
number from 0 to 2
28
. If a file system predominately has 400-byte files, a
fragment size of 512 would be the most efficient, since 4096-byte fragments
would be wasted space. The fragment is the smallest addressable unit of
storage.
The Journaled File System log
Multiple Journaled File Systems use a common log, called a JFS log, configured
to be 4 MB in size. For example, after initial installation, all file systems within the
root volume group use the logical volume hd8 as a common JFS log. The default
logical volume partition size is 4 MB, and the default log size is one partition;
therefore, the root volume group normally contains a 4 MB JFS log. When file
systems exceed 2 GB, or when the total amount of file system space using a
single log exceeds 2 GB, the default log size needs to be increased. The JFS log
is limited to a maximum size of 256 MB.
Maximum Journaled File System size
The maximum JFS size is defined when the file system is created. For example,
selecting a fragment size of 512 will limit the file system to a size of 8 GB (512 *
2
24
= 8 GB). When creating a JFS file system, the factors listed (nbpi, fragment
size, and allocation group size) need to be weighed carefully. The file system
size limitation is the minimum of NPBI * 2
24
or Fragment Size * 2
28
.
6.6.2 Creating a file system
Every file system in AIX corresponds to a logical volume. To create a Journaled
File System, use the following SMIT hierarchy:
1. Executing the SMIT fast path command smitty crjfs will show a screen
similar to Figure 6-20 on page 172.
Chapter 6. Storage management, LVM, and file systems 173
3. Select the volume group you want to add the new file system to by using the
arrow keys. In this case, since there is only one volume group (rootvg), only
rootvg is displayed. Select rootvg as your target volume group by pressing the
Enter key.
4. Once you select the target volume group, a screen similar to Figure 6-22 is
displayed.
Figure 6-22 Setting characteristics of the new file system
5. In the Size of file system (in 512 byte blocks) field, enter the size of the file
system you want to create. For example, if you want to create a file system of
4 MB in size, you can simply multiply the number of megabytes (four, in this
case) with 2048 to get the number of 512-byte blocks you will need to specify
to create a file system this large (8192, in this case).
174 IBM ^ Certification Study Guide - pSeries AIX System Administration
6. Next, in the MOUNT POINT field, enter the full path where you want your file
system to attach itself to the file system hierarchy. A mount point is a directory
or file at which the new file system, directory, or file is made accessible.
7. Press Enter to create the Journaled File System. The screen shown in
Figure 6-23 indicates the successful completion of the process.
Figure 6-23 smitty crjfs results
Note: In AIX, all of the I/O is in 4 KB blocks; however, space is allocated in
multiples of 512 byte blocks. This is done just to remain consistent with other
UNIX systems. The smallest file system that you can create is equal to one
PP; therefore, even if you specify that the number of blocks to be less than one
PP, the system will still create a file system equal to one PP. The following
example shows how to calculate the number of blocks for a given amount of
space in MB:
Since, 512 bytes = 1 block
Therefore, 1024 bytes = 2 blocks
and 1 MB = 2*1024 blocks
Therefore, x MB = x * 2048 blocks (Answer)
This indicates that the equivalent number of blocks for a file system of 2
MB are 4096 (enter this number in the Size of File System field).
Chapter 6. Storage management, LVM, and file systems 175
Alternatively, you can perform the same task on the command line using the
following command:
crfs -v jfs -g rootvg -a size=8192 -m /dummy
This will create a journaled file system of 4 MB with /dummy as the mount point in
the rootvg volume group.
6.6.3 Mounting a file system
Mounting is a concept that makes file systems, files, directories, devices, and
special files available for use at a particular location. It is the only way a file
system is made accessible. Once you have created the file system, the next task
is to make it available to your users. To do that, you must know how AIX
manages the patching of the newly created file systems into its file tree using the
mount points.
Figure 6-24 shows a file system mount point (/u/kenzie) before a file system is
mounted over it.
Figure 6-24 File tree view before mounting
Figure 6-25 shows a mounted file system /u/kenzie over the /u/kenzie mount
point.
Figure 6-25 File tree view after mounting
/ (root)
usr
utmpbin
terry
dave
kenzie
Mount Point
year month
week
/ (root)
usr
u
tmp bin
terry
dave
kenzie
Mount Point
year month
week
year month
week
176 IBM ^ Certification Study Guide - pSeries AIX System Administration
Mounting a file system using the command line
The following command shows how to mount a file system (/FileSystemX).
mount /FileSystemX
Alternatively, if you know the name of the device associated with your file system,
you can use the device name to mount your newly created file system.
If you want to mount all the file systems, you can use the following command to
mount all the file systems at one time.
mount {-a|all}
Mounting a file system using SMIT
A file system can be also be mounted using the following SMIT fast path
hierarchy.
1. Executing smitty mount will display the screen shown in Figure 6-26 on
page 177.
Note:
When a file system is mounted over a directory, the permissions of the root
directory of the mounted file system takes precedence over the
permissions of the mount point.
A common problem is failure of the pwd command. Without search
permission in the mounted-over directory, the pwd command returns the
following message:
pwd: Permission denied
This problem can be avoided by always setting the permissions of the
mounted-over directory to at least 111.
178 IBM ^ Certification Study Guide - pSeries AIX System Administration
3. Use the arrow keys to move down to DIRECTORY over which to mount.
4. Press F4 to get a list of the mount points that you have defined for your file
system (refer to Section 6.6.2, “Creating a file system” on page 171, to see
how you created a file system, and notice that you created a mount point for
your file system. You will use the same mount point to make your file system
available to the users). Pressing F4 shows a screen similar to Figure 6-28.
Figure 6-28 Selecting the mount point
5. Use the arrow keys to select the file system you want to mount. Press Enter to
make the selection. This will display the mount point you just selected in the
DIRECTORY over which to mount field.
6. Press Enter again and wait for the SMIT OK prompt, which indicates the
successful completion of the process.
Automatic mounting
Mounts can be set to occur automatically during system initialization. There are
two types of automatic mounts:
Those mounts that are required to boot and run the system. These file
systems are explicitly mounted by the boot process. The stanzas of such file
systems in the /etc/filesystems file have mount=automatic. When the
multi-user initialization starts, the /etc/rc script does not try to mount these file
systems again when it runs the mount all command. Similarly, when the
umount all command is run, these file systems are not unmounted.
Chapter 6. Storage management, LVM, and file systems 179
The second type of automatic mount is user-controlled. These file systems
are mounted during initialization by the /etc/rc script when it issues the mount
all command. The stanzas of user-controlled automatic mounts contain
mount=true in /etc/filesystems.
You can specify that a file system is to be mounted automatically by either the
mount all command or by the /etc/rc script at the initialization time. You do this
by setting the Mount AUTOMATICALLY at system restart field to TRUE when you
are creating a file system (see Figure 6-22 on page 173), or by using the chfs -A
yes file_system command. The following stanza from /etc/filesystems shows a
file system, which is mounted automatically:
/opt:
dev = /dev/hd10opt
vfs = jfs
log = /dev/hd8
mount = true
check = true
Displaying mounted file systems
The following example shows the use of the mount command without a flag to
display information about all the currently mounted file systems.
# mount
node mounted mounted over vfs date options
-------- --------------- --------------- ------ ------------ ---------------
/dev/hd4 / jfs Oct 25 18:20 rw,log=/dev/hd8
/dev/hd2 /usr jfs Oct 25 18:20 rw,log=/dev/hd8
/dev/hd9var /var jfs Oct 25 18:20 rw,log=/dev/hd8
/dev/hd3 /tmp jfs Oct 25 18:20 rw,log=/dev/hd8
/dev/lv01 /var/dce jfs Oct 25 18:21 rw,log=/dev/hd8
/dev/hd1 /home jfs Oct 27 15:14 rw,log=/dev/hd8
/dev/lvtest /test jfs Oct 27 15:17 rw,log=/dev/hd8
/dev/lv07 /auto1 jfs Oct 27 15:34 rw,log=/dev/hd8
6.6.4 Removing a file system
The following example shows the steps involved to remove a file system:
1. Using the mount command to check the file systems that are currently
mounted will display the following screen:
# mount
node mounted mounted over vfs date options
-------- --------------- --------------- ------ ------------ ---------------
/dev/hd4 / jfs Oct 25 18:20 rw,log=/dev/hd8
/dev/hd2 /usr jfs Oct 25 18:20 rw,log=/dev/hd8
/dev/hd9var /var jfs Oct 25 18:20 rw,log=/dev/hd8
/dev/hd3 /tmp jfs Oct 25 18:20 rw,log=/dev/hd8
180 IBM ^ Certification Study Guide - pSeries AIX System Administration
/dev/lv01 /var/dce jfs Oct 25 18:21 rw,log=/dev/hd8
/dev/hd1 /home jfs Oct 27 15:14 rw,log=/dev/hd8
/dev/lvtest /test jfs Oct 27 15:17 rw,log=/dev/hd8
/dev/lv07 /auto1 jfs Oct 27 15:34 rw,log=/dev/hd8
2. Identify if the file system you want to remove is shown in the list.
Yes Continue with Step 3.
No Go to Step 5.
3. Unmount the file system by using the umount command.
# umount filesystem_name
4. Repeat Step 1 to check whether the file system has successfully been
unmounted.
5. Using the SMIT fast path command smitty rmjfs to remove a Journaled File
System will display a screen similar to the one shown in Figure 6-29.
Figure 6-29 smitty rmjfs command
6. Press F4 to get a list of all the file systems that are defined on the system.
You will obtain a screen similar to Figure 6-30 on page 181.
Chapter 6. Storage management, LVM, and file systems 181
Figure 6-30 Selecting the file system to remove
7. Select the file system to be removed using the arrow keys and press Enter.
8. The name of the file system you just selected will be shown in the FILE
SYSTEM name field.
9. If you want to keep the directory name that was used to mount this file
system, press Enter to complete the command, otherwise, change the
Remove Mount Point field to YES and press Enter to complete the process.
Alternatively, you could replace steps 5 through 9 with the rmfs command.
#rmfs filesystem_name
To remove the mount point when the file system is removed, add the -r flag.
6.6.5 Increasing the size of a file system
AIX provides you with the ability to increase the size of a file system dynamically
provided you have enough free space available on your disk. File systems that
are low on space might create unanticipated problems.
Note: Whenever a file system is full, the system cannot write to it, and returns
the following error:
There is not enough room in the file system
182 IBM ^ Certification Study Guide - pSeries AIX System Administration
Increasing file system size using the command line
A file system can be increased by using the chfs command, as shown in the
following steps:
1. Use the df command to find out the current size of the file system.
2. Calculate the number of blocks you need to add.
3. On the command line, enter the following command:
chfs -a size=new_size_in_512-byte_blocks file_system_name
Filesystem size changed to new_size_in_512-byte_blocks
Increasing file system size using SMIT
To increase the file system size using SMIT, perform the following steps:
1. Run the smitty chjfs command to display a screen similar to Figure 6-31.
Figure 6-31 smitty chjfs command
2. Use the arrow keys to select the file system you want to change and press the
Enter key. A screen similar to Figure 6-32 on page 183 will be shown, which
will report the current file system attributes.
Chapter 6. Storage management, LVM, and file systems 183
Figure 6-32 Setting new characteristics of a file system
3. Enter the new file system size that you calculated in the SIZE of file system (in
512 byte block) field.
4. Press Enter. The SMIT OK prompt will indicate the successful completion of
the process.
6.6.6 Reducing the size of a file system
You might increase the size of a file system for a variety of reasons. For example,
you may increase the size of your /myfs file system to install a new product. If
you later de-install this product, the free space in the /myfs file system will
increase. Since this space has been allocated to the /myfs file system, it cannot
be used by any other file system.
The following example shows how to reduce the size of the /myfs file system.:
1. Make a backup of the /usr file system using any one of the following
commands:
– cpio
– backup
– tar - See Section 8.2.2, “How to backup the current directory” on
page 227. This section also covers the backup and cpio commands.
184 IBM ^ Certification Study Guide - pSeries AIX System Administration
– savevg - See Section 8.2.1, “Backing up a single volume group” on
page 226.
2. Remove the file system (/myfs) using the procedure discussed in
Section 6.6.4, “Removing a file system” on page 179.
3. Create a new file system using the same name and reduced size. You can
refer to Section 6.6.2, “Creating a file system” on page 171.
4. Restore the backup of the file system into this reduced file system by using
the procedure discussed in Section 8.3.3, “How to restore a directory” on
page 233.
Using a mksysb to reduce a file system
During the process of restoring the rootvg volume group from a mksysb, one of
the options is to
shrink file systems on the disks where you install them. When
you choose this option, the logical volumes and file systems within the volume
group are recreated to the minimum size required to contain the data.
User-defined volume groups can also be restored in this manner by using the -s
flag of the restvg command.
6.6.7 Checking file system consistency
The fsck command checks file system consistency and interactively repairs the
file system. The general syntax of the fsck command is as follows:
fsck [ -n ] [ -p ] [ -y ] [ -dBlockNumber ] [ -f ] [ -ii-NodeNumber ]
[ -o Options ] [ -tFile ] [ -V VfsName ] [ FileSystem1 - FileSystem2 ... ]
Note: If you enter a value that is less than the minimum size required to
contain the current data (indicated in the LV_MIN_LPs entry), the
reinstallation process will fail. Use the df -k command to see the
current blocks used in the file systems, then divide this number by 1024
to get the total MB of the file system.
Chapter 6. Storage management, LVM, and file systems 185
The flags commonly used with the fsck command and their meanings are
shown in Table 6-7.
Table 6-7 fsck command flags
The fsck command checks and interactively repairs inconsistent file systems.
You should run this command before mounting any file system. You must be able
to read the device file on which the file system resides (for example, the /dev/hd0
device).
Flag Description
-f Performs a fast check. Under normal circumstances, the only file
systems likely to be affected by halting the system without shutting
down properly are those that are mounted when the system stops.
The -f flag prompts the fsck command not to check file systems that
were unmounted successfully. The fsck command determines this by
inspecting the s_fmod flag in the file system superblock.
This flag is set whenever a file system is mounted and cleared when
it is unmounted successfully. If a file system is unmounted
successfully, it is unlikely to have any problems. Because most file
systems are unmounted successfully, not checking those file systems
can reduce the checking time.
-p Does not display messages about minor problems but fixes them
automatically. This flag does not grant the wholesale license that the
-y flag does and is useful for performing automatic checks when the
system is started normally. You should use this flag as part of the
system startup procedures, whenever the system is being run
automatically. This flag also allows parallel checks by group. If the
primary superblock is corrupt, the secondary superblock is verified
and copied to the primary superblock.
-tFile Specifies a file parameter as a scratch file on a file system other than
the one being checked if the fsck command cannot obtain enough
memory to keep its tables. If you do not specify the -t flag, and the fsck
command needs a scratch file, it prompts you for the name of the
scratch file. However, if you have specified the -p flag, the fsck
command will be unsuccessful. If the scratch file is not a special file,
it is removed when the fsck command ends.
-y Assumes a yes response to all questions asked by the fsck
command. This flag lets the fsck command take any action it
considers necessary. Use this flag only on severely damaged file
systems.
186 IBM ^ Certification Study Guide - pSeries AIX System Administration
Normally, the file system is consistent, and the fsck command merely reports on
the number of files, used blocks, and free blocks in the file system. If the file
system is inconsistent, the fsck command displays information about the
inconsistencies found and prompts you for permission to repair them. If the file
system cannot be repaired, restore it from backup.
Mounting an inconsistent file system may result in a system crash. If you do not
specify a file system with the FileSystem parameter, the fsck command will
check all the file systems with attribute check=TRUE in /etc/filesystems.
6.6.8 Initializing the JFS log device
The logform command initializes a logical volume for use as a JFS log device,
which stores transactional information about file system metadata changes and
can be used to roll back incomplete operations if the machine crashes. The
following is the general syntax of the logform command:
logform LogName
Note: By default, the /, /usr, /var, and /tmp file systems have the check
attribute set to False (check=false) in their /etc/filesystem stanzas. The
attribute is set to False for the following reasons:
1. The boot process explicitly runs the fsck command on the /, /usr, /var, and
/tmp file systems.
2. The /, /usr, /var, and /tmp file systems are mounted when the /etc/rc file
is run. The fsck command will not modify a mounted file system, and
fsck results on mounted file systems are unpredictable.
Note:
The logform command is destructive; it wipes out all data in the logical
volume.
Accidentally running this on a file system completely destroys the file
system’s data. If a log device is open due to its use by a mounted file
system, the file system should be unmounted prior to running logform
against the log device. The logform command destroys all log records on
existing log devices, which may result in file system data loss. You can
check to ensure that the log device is closed by running the following:
lsvg -l VGname
Chapter 6. Storage management, LVM, and file systems 187
6.6.9 Placement of the JFS log device
The JFS log logical volume should be placed on a different physical volume from
the most active file system, preferably on the disk with the lowest I/O utilization,
to increase parallel resource usage. Using a separate JFS log for each file
system is also supported. Special consideration, however, should be taken with
the placement of multiple JSF logs on the same physical disk, and avoided if
possible.
6.6.10 Large file enabled file systems
AIX Version 4.3 and later provides support for file sizes in excess of 2 GB. 64-bit
processes can open files without specifically indicating that they understand
large files.
With the large file support in AIX Version 4.2, there was no underlying support for
a file size in excess of 2 GB.
In file systems enabled for large files, file data stored before the 4 MB file offset is
allocated in 4096 byte blocks and the file data stored beyond the 4 MB file offset
is allocated with large disk blocks of 128 KB in size. The large disk blocks are
actually 32 contiguous 4096 byte blocks.
For example, a 132 MB file in a file system enabled for large files has 1024 4 KB
disk blocks and 1024 128 KB disk blocks. In a regular file system, the 132 MB file
would require 33 single indirect blocks (each filled with 1024 number of 4 KB disk
addresses). However, the large file geometry requires only two single indirect
blocks for the 132 MB file.
Determining large file enabled file systems
You can determine large file enabled file systems using the lsfs -q file_system
command as shown in Figure 6-33.
Figure 6-33 lsfs -q command output
The bf: output field in Figure 6-33 indicates a big file. This field specifies the file
system is a large file enabled, if it has a value of true.
188 IBM ^ Certification Study Guide - pSeries AIX System Administration
6.7 Troubleshooting file system problems
This section will discuss some of the problems encountered while managing LVM
and how to resolve them.
6.7.1 Recovering from super block errors
If you receive one of the following errors from the fsck or mount commands, the
problem may be a corrupted (or
dirty) superblock.
fsck: Not an AIX3 file system
fsck: Not an AIXV3 file system
fsck: Not an AIX4 file system
fsck: Not an AIXV4 file system
fsck: Not a recognized file system type
mount: invalid argument
The problem can be resolved by restoring the backup of the superblock over the
primary superblock using one of the following commands:
dd count=1 bs=4k skip=31 seek=1 if=/dev/lv00 of=/dev/lv00
The following command works only for AIX Version 4:
fsck -p /dev/lv00
Once the restoration process is completed, check the integrity of the file system
by issuing the fsck command.
fsck /dev/lv00
In many cases, restoration of the backup of the superblock to the primary
superblock will recover the file system. If this does not resolve the problem,
recreate the file system and restore the data from a backup.
6.7.2 Cannot unmount file systems
A file system cannot be unmounted if any reference is still active within that file
system. The following error message will be displayed:
Device busy
or
A device is already mounted or cannot be unmounted
The following situations can leave an open references to a mounted file system:
Files are open within a file system. Close these files before the file system
can be unmounted. The fuser command is often the best way to determine
Chapter 6. Storage management, LVM, and file systems 189
what is still active in the file system. The fuser command will return the
process IDs for all processes that have open references within a specified file
system as shown in the following example:
# fuser -xc /tmp
/tmp: 2910 3466 11654 26400
The process having an open reference can be killed by using the kill
command, and the unmount can be accomplished.
If the file system is still busy and still cannot be unmounted, this could be due
to a kernel extension that is loaded but exists within the source file system.
The fuser command will not show these kinds of references since a user
process is not involved. However, the genkex command will report on all
loaded kernel extensions.
File systems are still mounted within the file system. Unmount these file
systems before the file system can be unmounted. If any file system is
mounted within a file system, this leaves open references in the source file
system at the mount point of the other file system. Use the mount command
to get a list of mounted file systems. Unmount all the file systems that are
mounted within the file system to be unmounted.
A process is using a directory within the file system as its current working
directory. The fuser command appends a c to the process IDs of all
processes that are using a directory as their current working directory, and the
-u flag identifies the owner of the process. It can be used with the find
command as shown in the following example:
# find /home -type d -exec fuser -u {} \;
/home:
/home/lost+found:
/home/guest:
/home/kenzie: 3548c(kenzie)
For an interactive process, have the identified user change their current
working directory to a directory outside the file system, otherwise kill the
process, and the umount can be accomplished.
6.8 Summary of LVM commands
This section summarizes the key commands that have been used in different
sections of this chapter.
190 IBM ^ Certification Study Guide - pSeries AIX System Administration
6.8.1 PV commands
The following commands are most commonly used with physical volume related
tasks.
lsdev Lists devices in the ODM.
chdev Changes the characteristics of a device.
mkdev Adds a device to the system.
chpv Changes the state of the physical volume.
lspv Displays information about a physical volume within a volume
group.
migratepv Moves allocated physical partitions from one physical volume to
one or more other physical volumes.
6.8.2 VG commands
The following commands are most commonly used with volume group related
tasks:
mkvg Creates a new volume group.
extendvg Adds a physical volume to a volume group.
reducevg Removes a physical volume from a volume group.
chvg Changes a volume group.
lsvg Displays information about a volume group.
importvg Installs a volume group.
exportvg Removes a volume group.
reorgvg Reorganizes a volume group.
syncvg Synchronizes a volume group.
varyonvg Makes a volume group available for use.
varyoffvg Makes a volume group unavailable for use.
6.8.3 LV commands
The following are some of the most commonly used logical volume commands:
mklv Creates a logical volume.
lslv Lists the characteristics of a logical volume.
rmlv Removes a logical volume.
extendlv Increases the size of a logical volume.
Chapter 6. Storage management, LVM, and file systems 191
chlv Changes the characteristic of a logical volume.
mklvcopy Adds copies to a logical volume.
rmlvcopy Removes copies from a logical volume.
6.8.4 File system commands
The following is the list of file systems commands that have been discussed in
this chapter:
chfs Changes the characteristics of a file system.
crfs Adds a file system.
lsfs Displays the characteristics of a file system.
rmfs Removes a file system.
mount Makes a file system available for use.
fsck Checks file system consistency and interactively repairs the file
system.
umount Unmounts a previously mounted file system, directory, or file.
df Reports information about space on file systems.
6.9 Quiz
The following certification assessment questions help verify your understanding
of the topics discussed in this chapter.
1. While using the SMIT install menus to install an LPP, the response
yes has
been selected for the option: EXTEND file systems if space needed. After
successfully installing the LPP, the /usr file system appears to be
unnecessarily large. Which of the following actions can be performed to
reduce the size of the /usr file system?
A. Backup, unmount, remove, recreate and restore the file system.
B. Unmount, run defragfs /usr and the reducefs -size XXX /usr commands.
C. Boot from mksysb tape and follow the procedure to reduce the file system.
D. Update /etc/filesystems with the desired size for /usr and reboot the
system.
192 IBM ^ Certification Study Guide - pSeries AIX System Administration
2. A system administrator's daily monitoring has revealed a failing disk drive.
While examining the system, the administrator identified an unallocated drive.
Which of the following actions should be performed first to migrate the data
from the failing drive to the unallocated drive?
A. Migrate logical volumes to the new drive.
B. Add the unallocated drive to the volume group.
C. Create a copy of the file systems to the new drive.
D. Create a mirror of the logical volumes to the new drive.
3. Due to high I/O volume to several file systems, the system administrator has
decided to create a second JFS log volume to balance the I/O requests. After
creating the logical volume to serve as the JFS log, what must be done to
make the jfslog available for use?
A. Use the chvg command to enable the JFS log volume.
B. Use the chjfs command to enable the JFS log volume.
C. Use the logform command to format the logical volume.
D. Edit /etc/filesystems and add the logical volume name.
4. A system has been recovered from a hard disk failure and the failed disk has
been replaced with a new unformatted one. When the system administrator
varies on the volume group, an error message about a missing or unavailable
disk matches the one the system administrator replaced. Which of the
following commands will eliminate this error message?
A. cfgmgr
B. export VGName
C. mkdev -1 hdisk3
D. reducevg -df VGName PVID
The following are additional questions created by the authors to further test your
understanding of the topics.
1. The system administrator has created 20 file systems that are set to mount
each time the system boots. Which of the following is the
quickest method to
mount these file systems?
A. mount -a
B. Reboot the system.
C. /usr/lib/methods/cfgfs
D. Mount each individual file system.
Chapter 6. Storage management, LVM, and file systems 193
2. To increase the size of a file system, the system administrator must:
A. Unmount the file system.
B. Boot the system into single user mode.
C. Have enough free physical partitions within the volume group.
D. Back up the file system, change the size, and restore the file system.
3. To decrease the size of the /home file system, the system administrator must:
A. Use the chfs command.
B. Use the reducefs command.
C. Run the defragfs command and then use the reducefs command.
D. Back up, delete, redefine, and restore the file system.
4. What is the correct sequence of steps to mirror a volume group?
1. extendvg
2. mirroring
3. syncvg
4. set quorum
5. mkfscopy
6. reorgvg
A. 1, 2, 3, 4
B. 1, 5, 3, 4
C. 1, 2, 4, 6
D. 6, 5, 4, 3
5. Several error log entries indicate that hdisk5 is going bad. Before it completely
fails, the system administrator decides to copy the information from that disk
to the other five hard disks in that volume group. Which of the following
commands should be used?
A. copyfs
B. movelv
C. populatefs
D. migratepv
194 IBM ^ Certification Study Guide - pSeries AIX System Administration
6. A system has one internal disk drive (hdisk0) and one external disk drive
(hdisk1).
– hdisk0 is a 2.2 GB SCSI/2 Fastwide disk drive and contains a volume
group called rootvg.
– hdisk1 is a 4.5 GB SSA drive and contains a volume group called appsvg.
– The external SSA drive has over 3.0 GB of free space.
The system administrator would like to make a mirrored copy of a 500 MB
logical volume that currently is on hdisk0. What would prohibit the system
administrator from establishing a mirrored copy between the internal and
external disk drives?
A. The disks are not the same physical size.
B. The disks are not within the same volume group.
C. AIX does not support mirroring logical volume mirroring.
D. The disks are not the same drive type (for example, SSA verses SCSI/2).
7. Which of the following commands displays the status of a physical volume
(hdisk1) before adding it to a volume group called cdvg?
A. lsvg cdvg
B. chvg cdvg
C. lspv hdisk1
D. chpv hdisk1
8. What step must be taken prior to removing a file system?
A. Unmount the file system.
B. Remove the logical volume.
C. Delete the data from the file system.
D. Remove the NFS export for the file system.
Chapter 6. Storage management, LVM, and file systems 195
6.9.1 Answers
The following answers are for the assessment quiz questions.
1. C
2. B
3. C
4. D
The following answers are for the additional quiz questions.
1. A
2. C
3. D
4. A
5. D
6. B
7. C
8. A
6.10 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. List all the physical volumes, volume groups, logical volumes, physical
partitions, and file systems on your system.
2. Determine which disks the rootvg volume group resides on.
3. Add a new physical volume to your system and check to make sure the drive
is available.
4. Create a volume group named datavg on this new physical volume.
5. Create a file system named datafiles.
6. Unmount the datafiles file system.
7. Create a mirror of datavg.
8. Determine whether you have a disk quorum.
9. Determine how many VGDA and VGSA are there for your system.
10.Increase the size of the file system, datafiles.
196 IBM ^ Certification Study Guide - pSeries AIX System Administration
11.Reduce the file system, datafiles.
12.List the disks that a file system, datafiles, and a volume group, datavg, reside
on.
13.Remove the mirror of datavg and check to make sure the logical volume isn't
mirrored.
14.Remove the datavg volume group.
15.Migrate data from any volume group other than rootvg to an unallocated
drive.
© Copyright IBM Corp. 2001 197
Chapter 7. System paging space
To accommodate a large virtual memory space with a limited real memory space,
the system uses real memory as a work space and keeps inactive data and
programs on a disk. The area of the disk that contains this data is called the
system paging space. This chapter discusses the management of system paging
space related functions.
7
198 IBM ^ Certification Study Guide - pSeries AIX System Administration
7.1 Paging space overview
A page is a unit of virtual memory that holds 4 KB of data and can be transferred
between real and auxiliary storage.
A paging space, also called a swap space, is a logical volume with the attribute
type equal to paging. This type of logical volume is referred to as a paging space
logical volume or simply paging space. When the amount of free real memory in
the system is low, programs or data that have not been used recently are moved
from real memory to paging space to release real memory for other activities.
The installation creates a default paging logical volume (hd6) on drive hdisk0,
also referred as primary paging space.
The default paging space size is determined during the system customizing
phase of AIX installation according to the following standards:
Paging space can use no less than 16 MB, except for hd6. In AIX Version
4.2.1, hd6 can use no less than 32 MB, and in AIX Version 4.3 and later, no
less than 64 MB.
Paging space can use no more than 20 percent of the total disk space.
If real memory is less than 256 MB, paging space is two times real memory.
If real memory is greater than or equal to 256 MB, paging space is 512 MB.
7.1.1 Paging space considerations
The amount of paging space required by an application depends on the type of
activities performed on the system. If paging space runs low, processes may be
lost. If paging space runs out, the system may panic. When a paging space low
condition is detected, additional paging space should be defined. The system
monitors the number of free paging space blocks and detects when a paging
space shortage exists. The vmstat and topas commands obtain statistics related
to this condition. When the number of free paging space blocks falls below a
threshold known as the paging space warning level, the system informs all
processes (except the kernel process) of the low paging space condition.
Placement of paging spaces
The I/O from and to the paging spaces is random and is mostly one page at a
time. The reports from the vmstat and topas commands indicate the amount of
paging space I/O that is taking place. A sample output of the vmstat command is
shown in Figure 7-1 on page 199.
200 IBM ^ Certification Study Guide - pSeries AIX System Administration
To improve paging performance, you should use multiple paging spaces and
locate them on separate physical volumes whenever possible. More than one
paging space can be located on the same physical volume, however, we do not
recommend it.
Sizes of paging spaces
The general recommendation is that the sum of the sizes of the paging spaces
should be equal to at least twice the size of the real memory of the machine, up
to a memory size of 256 MB (512 MB of paging space). For memories larger than
256 MB, the following rule is recommended:
Total paging space = 512 MB + (memory size - 256 MB) * 1.25
Ideally, there should be several paging spaces of roughly equal size each on a
different physical disk drive. If you decide to create additional paging spaces,
create them on physical volumes that are more lightly loaded than the physical
volume in rootvg.
While the system is booting, only the primary paging space (hd6) is active.
Consequently, all paging-space blocks allocated during boot are on the primary
paging space. This means that the primary paging space should be somewhat
larger than the secondary paging spaces. The secondary paging spaces should
all be of the same size to ensure that the round-robin algorithm can work
effectively.
The lsps -a command provides a snapshot of the current utilization of each of
the paging spaces on a system, while the lsps -s command provides a
summary of the total active paging space and its current utilization.
Limitations of volume groups having paging space
Avoid adding paging space to the volume groups on portable disks in systems
prior to AIX 5L Version 5.1. Removing a disk that is online with an active paging
space will require a reboot to deactivate the paging space and, therefore, cause
user disruption.
Note: In versions prior to AIX 5L Version 5.1, a volume group that has a
paging space volume on it cannot be varied off or exported while the
paging space is active. Before deactivating a volume group having an
active paging space volume, ensure that the paging space is not activated
automatically at system initialization and then reboot the system.
Chapter 7. System paging space 201
7.2 Managing paging spaces
The following commands are used to manage paging space:
chps Changes the attributes of a paging space.
lsps Displays the characteristics of a paging space.
mkps Creates an additional paging space.
rmps Removes an inactive paging space.
swapon Activates a paging space.
swapoff Deactivates one or more paging spaces.
The swapon command is used during early system initialization (/sbin/rc.boot) to
activate the initial paging-space device. During a later phase of initialization,
when other devices become available, the swapon command is used to activate
additional paging spaces so that paging activity occurs across several devices.
Active paging spaces cannot be removed. To remove an active paging space, it
must first be made inactive. To accomplish this in AIX versions up to AIX Version
4.3, use the chps command so the paging space is not used on the next system
restart. Then, after restarting the system, the paging space is inactive and can be
removed using the rmps command. In AIX 5L Version 5.1, use the swapoff
command to dynamically deactivate the paging space, then proceed with the
rmps command.
The paging-space devices that are activated by the swapon -a command are
listed in the /etc/swapspaces file as shown in the following example. A paging
space is added to this file when it is created by the mkps -a command, removed
from the file when it is deleted by the rmps command, and added or removed by
the chps -a command.
# pg /etc/swapspaces
* /etc/swapspaces
*
* This file lists all the paging spaces that are automatically put into
* service on each system restart (the 'swapon -a' command executed from
* /etc/rc swaps on every device listed here).
*
* WARNING: Only paging space devices should be listed here.
*
Note: In AIX versions up to AIX Version 4.3, paging space cannot be
deactivated dynamically. It requires a system reboot. So, any maintenance
task that requires removal of paging space will have to be scheduled at an
appropriate time to minimize user disruption.
202 IBM ^ Certification Study Guide - pSeries AIX System Administration
* This file is modified by the chps, mkps and rmps commands and referenced
* by the lsps and swapon commands.
hd6:
dev = /dev/hd6
paging00:
dev = /dev/paging00
7.2.1 Displaying paging space characteristics
The lsps command displays the characteristics of paging spaces, such as the
paging space name, physical volume name, volume group name, size,
percentage of the paging space used, whether the space is active or inactive,
and whether the paging space is set to automatic. The paging space parameter
specifies the paging space whose characteristics are to be shown.
The following examples show the use of the lsps command with various flags to
obtain the paging space information. The -c flag will display the information in
colon format and paging space size in physical partitions.
# lsps -a -c
#Psname:Pvname:Vgname:Size:Used:Active:Auto:Type
paging00:hdisk1:rootvg:20:1:y:y:lv
hd6:hdisk1:rootvg:64:1:y:y:lv
# lsps -a
Page Space Physical Volume Volume Group Size %Used Active Auto Type
paging00 hdisk1 rootvg 80MB 1 yes yes lv
hd6 hdisk1 rootvg 256MB 1 yes yes lv
# lsps -s
Total Paging Space Percent Used
336MB 1%
7.2.2 Adding and activating a paging space
To make a paging space available to the operating system, you must add the
paging space, and then activate it. The total space available to the system for
paging is the sum of the sizes of all active paging-space logical volumes.
Note: You should not add paging space to volume groups on portable disks
because removing a disk with an active paging space will cause the
system to crash.
Chapter 7. System paging space 203
The following example shows the steps to create a new 20 MB paging space
logical volume:
1. Run the SMIT fast path smitty mkps to obtain a screen, as shown in
Figure 7-3.
Figure 7-3 smitty mkps command
2. Use the Arrow keys to highlight the rootvg volume group name, and then
press the Enter key to obtain a screen, as shown in Figure 7-4.
Figure 7-4 Add Another Paging Space attributes
3. Type 5 for the field SIZE of paging space (in logical partitions), 5 times 4 MB
results in a 20 MB paging logical volume.
4. Use the Tab key to toggle the field Start using this paging space NOW? from
no to yes, or use the F4 key to select it.
204 IBM ^ Certification Study Guide - pSeries AIX System Administration
5. Use the Tab key to toggle the field Use this paging space each time the
system is RESTARTED? from no to yes.
6. Press the Enter key to create the paging logical volume.
7. SMIT returns the new device name, paging01, with an OK prompt. Press the
F10 key to return to the command line.
8. You can now use the command lsps -a to check that the new device
(paging01) is added and active.
# lsps -a
Page Space Physical Volume Volume Group Size %Used Active Auto Type
paging01 hdisk1 rootvg 20MB 1 yes yes lv
paging00 hdisk1 rootvg 80MB 1 yes yes lv
hd6 hdisk1 rootvg 256MB 1 yes yes lv
7.2.3 Changing attributes of a paging space
You can change only the following two attributes for a paging space logical
volume.
Deactivate or activate a paging space for the next reboot.
Increase the size of an already existing paging space.
AIX 5L Version 5.1 adds the abilities to deactivate a paging space and to decrease
the size of a paging space without having to reboot.
Deactivating paging spaces
The following example shows how to deactivate a paging logical volume,
paging03:
1. Run the SMIT fast path command, smitty chps, to get to a PAGING SPACE
name prompt screen as shown in Figure 7-5.
Figure 7-5 smitty chps command
Chapter 7. System paging space 205
2. Use the Arrow keys to highlight the paging03 paging space name and then
press the Enter key.
3. Use the Tab key to toggle the field Use this paging space each time the
system is RESTARTED? from yes to no, as shown in Figure 7-6.
Figure 7-6 Changing attributes of paging space in AIX Version 4.3
4. Press Enter to change the paging03 paging logical volume.
5. When SMIT returns an OK prompt, you can press the F10 key to return to the
command line.
6. Reboot the system and run the lsps -a command to confirm that status of
paging03 has changed to inactive.
Dynamically deactivating a paging space in AIX 5L Version 5.1
The swapoff command deactivates paging spaces without requiring a reboot.
The swapoff command syntax is as follows:
# swapoff DeviceName { DeviceName ... }
Use the command swapoff /dev/paging03 to deactivate paging space paging03,
or use the SMIT fast path smitty swapoff as shown in Figure 7-7 on page 206.
206 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 7-7 smitty swapoff command
Increasing the size of a paging space
The following example shows how to increase the size of an already existing
paging space, paging03, by 20 MB.
1. Run the SMIT fast path command smitty chps to get to a PAGING SPACE
name prompt screen, as shown in Figure 7-5 on page 204.
2. Use the Arrow keys to highlight the paging03 paging space name, and then
press the Enter key.
3. Type 5 for the field NUMBER of additional logical partitions, as 5 times 4 MB
will result in a 20 MB increase in paging space.
4. Press the Enter key to change the paging03 paging logical volume.
5. When SMIT returns an OK prompt, you can press the F10 key to return to the
command line.
6. Run the lsps -a command to confirm that the size of paging03 has
increased.
Note: It is necessary to move all pages in use on the paging space being
deactivated to other paging spaces, therefore there must be enough space
available in the other active paging spaces.
Chapter 7. System paging space 207
Decreasing the size of a paging space
AIX 5L Version 5.1 introduces the chps -d command. This allows the size of a
paging space to be decreased without having to deactivate it, then reboot, then
remove the paging space, then recreate it with a smaller size, and then
reactivate it.
Use the chps -d command to decrease the size of paging03 by 2 logical
partitions as shown in the following example:
# chps -d 2 paging03
shrinkps: Temporary paging space paging04 created.
shrinkps: Paging space paging03 removed.
shrinkps: Paging space paging03 recreated with new size.
7.2.4 Removing a paging space (except hd6)
The following example shows the steps involved in removing an existing paging
space, paging00, in AIX versions up to AIX Version 4.3.
1. Refer to Section 7.2.3, “Changing attributes of a paging space” on page 204
to change the attributes of paging space, paging00, so that it will not be active
after a reboot.
2. Reboot the system by executing the shutdown -Fr command.
3. When the system is up, login in as root and run the fast path smitty rmps to
get to the menu with the title Remove a Paging Space. Alternatively, you can
use SMIT by executing the following commands:
a. Run smitty.
b. Select System Storage Management (Physical & Logical Storage).
c. Select Logical Volume Manager.
d. Select Paging Space.
Note: Removing default paging spaces incorrectly can prevent the system
from restarting. This procedure should only be attempted by experienced
system administrators. You must deactivate the paging space before you can
remove it, which requires a reboot.
Check the primary dump device you are using by executing the command
sysdumpdev -l. You cannot remove the default dump device. You must
change the default dump device to another paging space or logical volume
before removing the paging space. To change the default dump device, use
the following command:
sysdumpdev -P -p /dev/new_dump_device
208 IBM ^ Certification Study Guide - pSeries AIX System Administration
e. Select Remove a Paging Space to get to the same menu.
4. Press the F4 key to generate a list of paging logical volumes.
5. Use the Arrow keys to highlight the paging00 logical volume name, and then
press the Enter key three times (once to enter the name in the field, once to
get the warning, and the third time to run the command).
6. When SMIT returns an OK prompt with the following message, you can press
the F10 key to return to the command line.
rmlv:Logical volume paging00 is removed
The following example shows the error message you get when you try to remove
an active paging space, paging01.
# lsps -a
Page Space Physical Volume Volume Group Size %Used Active Auto Type
paging03 hdisk1 rootvg 4MB 0 no no lv
paging01 hdisk1 rootvg 20MB 1 yes yes lv
paging00 hdisk1 rootvg 80MB 1 yes yes lv
hd6 hdisk1 rootvg 256MB 1 yes yes lv
# rmps paging01
0517-062 rmps: Paging space paging01 is active.
0517-061 rmps: Cannot remove paging space paging01.
The following example shows how you would remove paging space paging00 in
AIX 5L Version 5.1:
# swapoff /dev/paging00
# rmps paging00
rmlv: Logical volume paging00 is removed.
7.2.5 Managing default paging space (hd6)
The default installation creates a paging logical volume (hd6) on drive hdisk0,
which contains part or all of the busy / (root) and /usr file systems. System
administrators may want to reduce the default paging space or move it to a less
busy hard disk to:
Enhance storage system performance by forcing paging and swapping to
other disks in the systems that are less busy.
Conserve disk space on hdisk0.
A special procedure is required to remove the default paging space (hd6). This
paging space is activated during boot time by shell scripts that configure the
system. To remove one of the default paging spaces, these scripts must be
altered, and a new boot image must be created.
Chapter 7. System paging space 209
The following example shows the command to check your logical volume and file
system distribution across a physical volume, hdisk1:
# lspv -l hdisk1
hdisk1:
LV NAME LPs PPs DISTRIBUTION MOUNT POINT
hd5 2 2 02..00..00..00..00 N/A
hd6 64 64 00..64..00..00..00 N/A
paging01 5 5 00..05..00..00..00 N/A
hd8 1 1 00..00..01..00..00 N/A
hd4 1 1 00..00..01..00..00 /
hd2 73 73 00..00..73..00..00 /usr
hd9var 1 1 00..00..01..00..00 /var
hd3 4 4 00..00..04..00..00 /tmp
hd1 1 1 00..00..01..00..00 /home
paging00 20 20 00..00..20..00..00 N/A
paging03 1 1 00..00..01..00..00 N/A
Reducing the size of hd6 paging space
The following example shows the steps involved in reducing the size of paging
space hd6 from 160 MB to 120 MB. The steps in the following procedures are all
necessary - even those not directly related to hd6. The additional steps are
needed because a paging space cannot be deactivated while the system is
running.
1. Create a temporary paging space on rootvg by executing the following
command:
mkps -a -n -s 30 rootvg hdisk0
This command outputs the name of the paging space (paging00 if no others
exist).
2. Use the following command to deactivate the hd6 paging spaces in
preparation for the reboot later in the procedure.
chps -a n hd6
Note:
AIX Version 4.2.1 and later does not support reducing the size of hd6
below 32 MB. If this is done, the system will not boot.
If you decide to reduce hd6, you must leave enough space for the software
in rootvg. A rule of thumb for reducing hd6 paging space is to leave enough
space to match physical memory. To find out the amount of physical
memory, use the following command:
lsattr -E -l sys0 -a realmem
210 IBM ^ Certification Study Guide - pSeries AIX System Administration
3. Change the paging space entry in the /sbin/rc.boot file from:
swapon /dev/hd6
to
swapon /dev/paging00.
4. Run the following command to check the primary dump device designation.
# sysdumpdev -l
primary /dev/hd6
secondary /dev/sysdumpnull
copy directory /var/adm/ras
forced copy flag TRUE
always allow dump FALSE
5. If the primary dump device is hd6, change it to some other paging space. The
following command shows how to change the primary dump device to
paging00:
# sysdumpdev -P -p /dev/paging00
primary /dev/paging00
secondary /dev/sysdumpnull
copy directory /var/adm/ras
forced copy flag TRUE
always allow dump FALSE
6. Create a bootable image with the bosboot command for a hard disk image.
This step is required to update the system image used during initialization to
reflect the changes made to rc.boot.
bosboot -d /dev/hdisk0 -a
7. Put the system key (if present) in the normal position and use the following
command, which will both shutdown the operating system and reboot it.
shutdown -r
8. After the system reboots, remove the hd6 paging space.
rmps hd6
9. Create a new paging space logical volume of the size 120 MB for the hd6
paging space.
mklv -t paging -y hd6 rootvg 30
10.Use the lsps -a command to verify the reduced size of the default paging
space hd6.
11.Change the primary dump device designation back to be the paging space
hd6.
sysdumpdev -P -p /dev/hd6
Chapter 7. System paging space 211
12.Change the paging space entry in the /sbin/rc.boot file from:
swapon /dev/paging00
to
swapon /dev/hd6.
13.Create a bootable image with the bosboot command for a hard disk image.
bosboot -d /dev/hdisk0 -a
14.Run the following command to make the new hd6 paging space automatically
activate when the system reboots.
chps -a y hd6
15.Run the following command to change the attribute of temporary paging
space, paging00, so that it does not automatically activate after the next
reboot.
chps -a n paging00
16.Put the system key (if present) in the normal position and use the following
command to shutdown and reboot the system:
shutdown -r
17.After the system reboots, remove the temporary paging space.
rmps paging00
Reducing hd6 in AIX 5L Version 5.1
You can use the chps -d command to dynamically reduce the size of the primary
paging space hd6. This command will prevent you from decreasing the size of
hd6 below 32 MB or actually deleting it. If you decrease the primary paging
space, a temporary boot image and a temporary /sbin/rc.boot pointing to this
temporary primary paging space will be created to make sure the system is
always in a state where it can be safely rebooted.
Moving the hd6 paging space to another volume group
Moving a paging space with the name hd6 from rootvg to another volume group
is not recommended because the name is hard-coded in several places.
Only the paging spaces in rootvg will be active during the second phase of the
boot process, and having no paging space in rootvg could severely affect system
boot performance. If you want the majority of paging space on other volume
groups, it is better to make hd6 as small as possible (the same size as physical
memory) and then create larger paging spaces on other volume groups.
212 IBM ^ Certification Study Guide - pSeries AIX System Administration
Moving the hd6 paging space within the same VG
Moving the default paging space from hdisk0 to a different disk within the same
volume group does not require a system reboot.
The following example shows the command to move the default (hd6) paging
space from hdisk0 to hdisk1.
migratepv -l hd6 hdisk0 hdisk1
This may take a few minutes depending upon the size of the paging space.
7.3 Quiz
The following are questions created by the authors to further test your
understanding of the topics.
1. The system administrator realizes that paging space, paging12, must first be
removed from hdisk12. Which of the following is the correct sequence of
events for an older AIX system?
A. chps -an paging12, reboot, rmps paging12
B. swapoff paging12, rmps paging12
C. swapoff paging12, reboot, rmps paging12
D. chps -an paging12, swapoff paging12, rmps paging12
2. A customer would like to remove an unneeded, but active, paging space
called paging00. What is proper sequence of steps to accomplish this?
A. Remove the paging space by using the rmps command and reboot the
system.
B. Disable the paging space by using the chps command, reboot the
system, and remove the paging00 logical volume by using the rmps
command.
C. Disable the paging space by using the chps command, remove the
paging00 logical volume by using the rmps command, and reboot the
system.
D. Disable the paging space by using the chps command, reboot the
system, and remove the paging00 logical volume by using the rmlv
command.
Chapter 7. System paging space 213
3. A system administrator would like to list all of the paging spaces residing on
the server. What is the correct syntax of the command to accomplish this?
A. lsps -a
B. lsps -s
C. lsps -l
D. lsps -all
7.3.1 Answers
The following answers are for the quiz questions.
1. A
2. B
3. A
7.4 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Determine the paging spaces on a system by using the lsps command.
2. Add a new paging space logical volume of size of 5 MB to the system.
3. Discuss all the steps involved in decreasing the size of the default paging
space.
4. Discuss the precautions you would take before removing a paging space.
5. How can you change the primary dump device?
6. How can you move the hd6 paging space from one hdisk to another within the
same volume group?
7. Which command will display the paging activity status on the system?
8. Increase the paging space logical volume size by 10 MB.
9. Discuss how the process of decreasing the hd6 paging space is different from
decreasing any other paging space on the system.
214 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 215
Chapter 8. System backup, restores,
and availability
There are various commands you can use to make backups of systems. The
following is a list of the most common commands for backups. A short description
of each is given here with a list of their respective flags in Table 8-1 on page 216.
tar The tar command manipulates archives by writing files to, or
retrieving files from, an archive storage medium. The files used by
the tar command are represented by the File parameter. If the File
parameter refers to a directory, then that directory and, recursively, all
files and directories within it are referenced as well.
cpio The cpio command copies files into and out of archive storage and
directories.
dd The dd command reads the InFile parameter or standard input, does
the specified conversions, then copies the converted data to the
OutFile parameter or standard output. The input and output block
size can be specified to take advantage of raw physical I/O.
pax The pax command should be the archive of choice for system dumps
and images greater than 2 GB in size.
mksysb The mksysb command creates an installable image of the root volume
group either in a file or onto a bootable tape.
savevg The savevg command saves non-root volume groups.
8
216 IBM ^ Certification Study Guide - pSeries AIX System Administration
backup The backup command creates copies of your files on a backup
medium, such as a magnetic tape or diskette. The copies are in one
of the two backup formats: Either specific files backed up (using the -i
flag), or the entire file system backed up by i-node.
restore The restore command reads archives created by the backup
command and extracts the files stored on them. These archives can
be in either file-name or file-system format.
restvg Use the restvg command to restore a volume group.
tctl Use the tctl command to control a tape device.
Table 8-1 List of backup commands and flags
Command Flags Description
tar -x Extracts the files from the archive.
-c Creates a new archive and writes the files
specified.
-t Lists the files in the order in which they appear in
the archive.
-f Archive Uses the Archive variable as the archive to be read
or written. For example, /dev/fd0.
-p Says to restore fields to their original modes
ignoring the current umask.
-v Lists the name of each file as it is processed.
cpio -i Reads from standard input an archive file created
by the cpio -o command and copies from it the files
with names that match the Pattern parameter.
-o Reads file path names from standard input and
copies these files to standard output.
-c Reads and writes header information in ASCII
character form. If a cpio archive was created using
the -c flag, it must be extracted with a -c flag.
-v Lists file names.
-d Creates directories as needed.
-u Copies unconditionally. An older file now replaces a
newer file with the same name.
-m Retains previous file modification time. This flag
does not work when copying directories.
Chapter 8. System backup, restores, and availability 217
-B Performs block input and output using 512 bytes to
a record.
dd if=InFile Specifies the input file name; standard input is the
default.
of=OutFile Specifies the output file name; standard output is
the default.
skip=SkipInput
Blocks
Skips the specified SkipInputBlocks value of input
blocks before starting to copy.
pax -a Appends files to the end of an archive.
-f Archive Specifies the path of an archive file to be used
instead of standard input (when the -w flag is not
specified) or standard output (when the -w flag is
specified but the -r flag is not).
-r Reads an archive file from the standard input.
-v Writes information about the process. If neither the
-r or -w flags are specified, the -v flag produces a
verbose table of contents; otherwise, archive
member path names are written to standard error.
-w Writes files to the standard output in the specified
archive format.
-x Format Specifies the output archive format. If no format is
provided, pax uses the pax format by default.
mksysb -e Excludes files listed in the /etc/exclude.rootvg file
from being backed up.
-i Calls the mkszfile command, which generates the
/image.data file automatically during a backup.
-m Calls the mkszfile command to generate map files.
-X Automatically expands /tmp as necessary.
savevg -i Creates the data file by calling the mkvgdata
command.
-f Device Specifies the device or file name on which the
image is to be stored. The default is the /dev/rmt0
device.
-e Excludes files specified in the /etc/exclude.vgname
file from being backed up by this command.
Command Flags Description
218 IBM ^ Certification Study Guide - pSeries AIX System Administration
backup -i Specifies that files be read from standard input and
archived by file name.
-p Specifies that the files be packed, or compressed,
before they are archived. Only files of less than 2
GB are packed. This option should only be used
when backing up files from an inactive file system.
Modifying a file when a backup is in progress may
result in corruption of the backup and an inability to
recover the data. When backing up to a tape device
that performs compression, this option can be
omitted.
-q Indicates that the removable medium is ready to
use. When you specify the -q flag, the backup
command proceeds without prompting you to
prepare the backup medium. Press the Enter key to
continue.
-u Updates /etc/dumpdates with time, date, and level
of the last incremental backup.
-v Causes the backup command to display additional
information about the backup.
restore -d Indicates that, if the File parameter is a directory, all
files in that directory should be restored. This flag
can only be used when the archive is in filename
format.
-f Device Specifies the input device. To receive input from a
named device, specify the Device variable as a path
name (such as /dev/rmt0). To receive input from the
standard output device, specify a - (minus sign).
-q Specifies that the first volume is ready to use and
that the restore command should not prompt you to
mount the volume and press Enter.
-r Restores all files in a file system archive.
-s SeekBackup Specifies the backup to seek and restore on a
multiple-backup tape archive. The -s flag is only
applicable when the archive is written to a tape
device. To use the -s flag properly, a
no-rewind-on-close and no-retension-on-open tape
device, such as /dev/rmt0.1 or /dev/rmt0.5, must be
specified.
Command Flags Description
Chapter 8. System backup, restores, and availability 219
8.1 The mksysb command
The mksysb command creates a bootable image of all mounted file systems on
the rootvg volume group. You can use this backup command to reinstall a system
to its original state.
The tape format includes a BOS boot image, a BOS install image, and a dummy
table of contents (TOC) followed by the system backup (root volume group)
image. The root volume group image is in backup-file format starting with the
data files and then any optional map files.
User-defined paging spaces and raw devices are not backed up.
-t Displays information about the backup archive. If
the archive is in file-system format, a list of files
found on the archive is written to standard output.
-T Displays information about the backup archive. If
the archive is in file-name format, the information
contained in the volume header and a list of files
found on the archive are written to standard output.
-v Displays additional information when restoring.
-x Restores individually named files specified by the
File parameter.
restvg -f Device Specifies the device name of the backup media.
The default is /dev/rmt0.
-p PPsize Specifies the number of megabytes in each
physical partition. If not specified, restvg uses the
best value for the PPsize, dependent upon the
largest disk being restored to.
-s Specifies that the logical volumes be created at the
minimum size possible to accommodate the file
systems.
tctl -b Specifies, in bytes, the block size used to read and
write to the tape device.
-f Specifies the tape device to use.
Command Flags Description
220 IBM ^ Certification Study Guide - pSeries AIX System Administration
8.1.1 The data layout of a mksysb tape
The layout of a mksysb tape is shown in Figure 8-1.
Figure 8-1 Layout of a mksysb tape
The BOS boot image contains a copy of the system’s kernel and device drivers
needed to boot from the mksysb tape. It is created by the bosboot command.
There are three important files in the mkinsttape image (the second image of the
mksysb tape): ./tapeblksz, ./bosinst.data and ./image.data. The ./tapeblksz file
contains the block size the tape drive was set to when the mksysb command was
run.
The ./bosinst.data file allows you to specify the requirements at the target system
and how the user interacts with the target system. This file contains the
customized BOS install procedures and dictates how the BOS install program will
behave. You can customize this file before issuing the mksysb command or use a
procedure to customize this file after the image backup is done.
The ./image.data file contains information describing the image installed during
the BOS installation process. This information includes the sizes, names, maps,
and mount points of logical volumes and file systems in the rootvg. You can
customize this file before using the mksysb command, or run mksysb -i to
generate a new ./image.data file on the tape during a backup. The mkszfile
command generates the ./image.data file. The ./image.data file is arranged in
stanza format. Each stanza contains one or more fields. The most important
fields are:
SHRINK When set to YES, causes the system to create the smallest file
systems required to contain all the data in the file system.
BOS boot image mkinsttape image dummy .toc rootvg data ...
Blocksize=512 Blocksize=512 Blocksize=512 Tape Drive BS
Kernel
Device Drivers
./tapeblksz
./image.data
./bosinst.data
commands
Dummy TOC rootvg
mounted File Systems
Chapter 8. System backup, restores, and availability 221
BOSINST_FILE Provides the full path name of a file or command to execute
after the BOS install completes.
EXACT_FIT When set to YES, causes the system to place logical volumes
on the disk according to the physical partition maps that were
generated with -m flag of the mksysb command.
The dummy table of contents (TOC) is used so that the mksysb tape contain the
same number of images as a BOS install tape.
The rootvg data area contains all data in the rootvg volume group backed up by
the mksysb command. The mksysb command uses the backup command to save
the contents of mounted JFS data in rootvg, excluding raw data.
8.1.2 Excluding file systems from a backup
When you need to make a mksysb backup of a system, and you want to exclude
some data file systems from the system, you need to edit the /etc/exclude.rootvg
file. If, for example, you want to exclude the file systems /usr and /tmp from your
mksysb backup, add the following:
/usr/
/tmp/
Make sure there are no empty lines in this file. You can list the contents of the file
as follows:
# cat /etc/exclude.rootvg
/usr/
/tmp/
Then run the mksysb command using the -e flag to exclude the contents of the
exclude.rootvg file as follows:
mksysb -e /dev/rmt0
8.1.3 How to create a bootable system backup
The mksysb command creates a bootable image of the rootvg file system either
in a file system directory onto a bootable tape, and is used to restore a system
after a system failure or for system cloning.
To use smitty to create a bootable system backup, follow the steps below:
1. Run the smitty Command. Select the System Storage Management
(Physical & Logical Storage) field as shown in Figure 8-2 on page 222.
Chapter 8. System backup, restores, and availability 223
3. In the System Backup Manager window, select the Back Up the System field
as shown in Figure 8-4.
Figure 8-4 System Backup Manager menu
4. In the Back Up the System menu, select Backup DEVICE or FILE field. This is
where you would select your backup device. If you press F4, it will give you a
list of backup devices. Choose the device you want, and then press Enter as
shown in Figure 8-5 on page 224.
224 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 8-5 Back Up the System menu
5. The COMMAND STATUS screen is now displayed. Figure 8-6 on page 225 is
a screen of what information is being displayed during the backup process. In
Figure 8-7 on page 225 is the display for the successful completion of the
backup process.
6. The system has now created a bootable system backup.
Chapter 8. System backup, restores, and availability 225
Figure 8-6 COMMAND STATUS screen during operation
Figure 8-7 COMMAND STATUS screen after operation
226 IBM ^ Certification Study Guide - pSeries AIX System Administration
8.1.4 Using mksysb to back up a user volume group
You can run mksysb on rootvg; You cannot run mksysb against a user volume
group. If you want to back up a user volume group, you must use savevg, tar,
cpio, or backup.
8.2 Backing up user information
To backup user information, you can use one of the following commands:
savevg Finds and backs up all files belonging to a specified volume group.
tar Manipulates archives by writing files to, or retrieving files from, an
archive storage medium.
cpio Copies files into and out of archive storage and directories.
backup Creates copies of your files on a backup medium.
8.2.1 Backing up a single volume group
The savevg command finds and backs up all files belonging to a specified volume
group. A volume group must be varied on, and the file systems must be mounted.
The savevg command uses the data file created by the mkvgdata command.
To back up the uservg volume group and create a new uservg.data file, do the
following:
1. Check which volume group you want to back up.
# lsvg
rootvg
uservg
2. If you are satisfied that the volume group that must be backed up is uservg,
proceed with the backup as follows:
# savevg -if /dev/rmt0 uservg
Creating list of files to back up....
Backing up 9077 files..................................
4904 of 9077 files (54%)...................................
8798 of 9077 files (96%)...................................
8846 of 9077 files (97%)...................................
9029 of 9077 files (99%)...................................
0512-038 savevg: Backup Completed Successfully.
Chapter 8. System backup, restores, and availability 227
8.2.2 How to backup the current directory
To back up your current directory to the tape device /dev/rmt0, use the following
example. First, check that you are in the correct directory and then list the
contents of the directory:
# cd /userdirectory
# pwd
/userdirectory
# ls -l
total 1808
-rw-r--r-- 1 root system 0 Oct 22 18:20 DKLoadLog
-rw-r--r-- 1 root system 0 Oct 22 18:20 adnan.gif
-rw-r--r-- 1 root system 0 Oct 22 18:20 aixhelp
-rw-r--r-- 1 root system 51200 Oct 22 18:20 backup1
-rw-r--r-- 1 root system 0 Oct 22 18:20 cde-help
-rw-r--r-- 1 root system 0 Oct 22 18:20 cde-main
-rw-r----- 1 root system 25 Oct 22 18:20 cfgvg.out
-rw-r--r-- 1 root system 0 Oct 22 18:20 dtappint.log
-rw-r--r-- 1 root system 0 Oct 22 18:20 filelist
-rw-r--r-- 1 root system 0 Oct 22 18:20 httpd-pid
-rw-r--r-- 1 root system 0 Oct 22 18:20 mk_netboot
-rw-r--r-- 1 root system 0 Oct 22 18:20 nim1.gif
-rw-r--r-- 1 root system 0 Oct 22 18:20 nimM.gif
drwxr-xr-t 2 root system 1024 Oct 22 18:20 tmp
-rw-r--r-- 1 root system 0 Oct 22 18:20 xlogfile
-rwxr-x--x 1 root system 864256 Oct 22 18:20 xv
Now that you know what is in the directory, you can now back it up using the
following command:
# tar -cvf /dev/fd0 *
a DKLoadLog 0 blocks.
a adnan.gif 0 blocks.
a aixhelp 0 blocks.
a backup1 100 blocks.
a cde-help 0 blocks.
a cde-main 0 blocks.
a cfgvg.out 1 blocks.
a dtappint.log 0 blocks.
a filelist 0 blocks.
a httpd-pid 0 blocks.
a mk_netboot 0 blocks.
a nim1.gif 0 blocks.
a nimM.gif 0 blocks.
a tmp
a tmp/.strload.mutex 0 blocks.
a tmp/.oslevel.mlinfo.cache 53 blocks.
a xlogfile 0 blocks.
a xv 1688 blocks.
228 IBM ^ Certification Study Guide - pSeries AIX System Administration
The flags used are -c to create the archive, -v to list the archive contents, and -f
to select the device. A more comprehensive list of flags can be found in Table 8-1
on page 216.
There are two other commands that you can use to create backups. Using the
scenario of backing up /userdirectory, you can either use backup or cpio.
Using the backup command:
# cd /userdirectory
# find . -depth | backup -i -f /dev/rmt0
This will do a backup using relative path names, which means that when you
restore the information using the restore command, you need to be in the
/userdirectory directory, or else it will restore the information into your current
directory.
Using the cpio command:
# cd /
# find /userdirectory -print | cpio -o -c -v -B > /dev/rmt0
This will back up the information using absolute path names. This information
is restored using the cpio command with the -i flag. You can restore this from
anywhere, and it will restore to the directory /userdirectory.
Relative or absolute path names can be used by either the backup command or
the cpio command.
8.2.3 Incremental backups
The backup command can allow an administrator to make sets of incremental
backups over periods of time. This is useful for storing data that changes often on
the system. The syntax for the command is shown in the following example:
# backup -0 -uf /dev/rmt0 /home
Note: The tar command is one of very few commands that does not
require a - (minus) sign before a flag.
Note: The -print flag for the find command can be interchanged with the
-depth flag equally for backup commands.
Chapter 8. System backup, restores, and availability 229
When the -u flag is used with the backup command, the system will do an
incremental backup of user data according to the -level number specified. A level
0 backup will back up all system data in the specified file systems. Each
subsequent level will back up only the data that has changed since the previous
level backup. For example, a level 5 backup will only back up the data that has
changed after the level 4 backup was made. Levels can range from 0 to 9. By
default, the backup command without any parameters will run a level 9 backup.
If you want to design a weekly backup schedule to back up data that has
changed in the /data file system nightly, with a full backup done every Sunday,
the backup command can easily do this task.
On Sunday, the system would run:
# backup -0 -uf /dev/rmt0 /data
On Monday, the system would run:
# backup -1 -uf /dev/rmt0 /data
On Saturday, the system would run:
# backup -6 -uf /dev/rmt0 /data
Information regarding the date, time, and level of each incremental backup is
written to the /etc/dumpdates file. Data is stored in the following format:
/dev/lv01 0 Mon Jun 04 14:00:00 2001
/dev/lv01 1 Wed Dec 05 14:00:00 2001
8.3 Restoring information from backup media
When you restore information, you are taking information that you backed up in
the previous section and using one of the restore methods discussed in the
following sections.
8.3.1 The tctl command
The tctl command sends subcommands to a streaming tape device, like
/dev/rmt0. This command can manipulate tapes easily for data restoration. The
general syntax of the tctl command is as follows:
tctl [ -f Device ] [ eof | weof | fsf | bsf | fsr | bsr | rewind | offline |
rewoffl | erase | retension | reset | status ] [ Count ]
230 IBM ^ Certification Study Guide - pSeries AIX System Administration
If you do not specify the Device variable with the -f flag, the TAPE environment
variable is used. The most common subcommands are shown in Table 8-2 on
page 230.
Table 8-2 Common tctl subcommands
8.3.2 How to restore a file
For this example, you will restore the file /etc/hosts from a tape device /dev/rmt0.
You can use one of the following commands, depending on what command was
used to do the backup:
mksysb
There are three images (the BOS boot image, mkinsttape image, and dummy
TOC) that precede the backup files in a mksysb. You can move past them using
mt or tctl and the no-rewind option on the tape, or you can use the -s4 flag in
the restore command.
Rewind the tape to the beginning by using the following:
tctl -f /dev/rmt0 rewind
Subcommand Description
rewind Rewinds the tape.
rewoffl or offline Rewinds the tape and takes the tape drive offline. This will
unload or eject the tape when appropriate. The tape must be
reinserted, or another tape must be loaded before the device
can be used again.
status Displays status information about the specified tape device.
reset Sends a bus device reset (BDR) to the tape device. The BDR
will only be sent if the device cannot be opened and is not busy.
Once complete, the system will return the cursor to a prompt
without any notification.
fsf Count Moves the tape forward by the number of file marks specified
by the Count parameter, and positions it on the end-of-tape
(EOT) side of the file mark.
bsf Count Moves the tape backward by the number of file marks specified
by the Count parameter, and positions it on the
beginning-of-tape (BOT) side of the file mark. If the bsf
subcommand attempts to move the tape past the beginning,
the tape will rewind and the tctl command returns EIO.
Chapter 8. System backup, restores, and availability 231
List the information on the backup media by using the following:
# restore -T -d -v -q -s4 -f /dev/rmt0.1
New volume on /dev/rmt0.1:
Cluster size is 51200 bytes (100 blocks).
The volume number is 1.
The backup date is: Tue Oct 27 10:15:25 CST 1998
Files are backed up by name.
The user is root.
.......... (Lines Removed)
528 ./tmp/vgdata/rootvg/hd1.map
972 ./tmp/vgdata/rootvg/hd2.map
48 ./tmp/vgdata/rootvg/hd3.map
36 ./tmp/vgdata/rootvg/hd4.map
588 ./tmp/vgdata/rootvg/hd9var.map
0 ./etc
901 ./etc/hosts
0 ./home
0 ./home/lost+found
0 ./home/guest
0 ./home/ftp
254 ./home/ftp/.profile
0 ./home/ftp/bin
18774 ./home/ftp/bin/ls
0 ./home/ftp/etc
0 ./home/ftp/pub
150841 ./home/ftp/pub/aix-1-let.ps
.......... (Lines Removed)
The total size is 509575953 bytes.
The number of archived files is 37773.
This screen scrolls down showing you all the files on the backup medium. If
you want to show only the header information, you can leave out the -T and -v
flags.
Change to the /etc/ directory and list all files with the word hosts in them.
Notice that the hosts file is missing.
# cd /etc
# ls -l hosts*
-rw-r--r-- 1 root system 2060 Aug 25 09:41 hosts.equiv
-rw-rw-r-- 1 root system 1906 Aug 25 09:41 hosts.lpd
Change to the root directory and check your current directory as in the
following:
# cd /
# pwd
/
232 IBM ^ Certification Study Guide - pSeries AIX System Administration
Rewind the tape device using the following command:
tctl -f /dev/rmt0 rewind
Restore the file that you want. Notice the . (point) before /etc/hosts; this needs
to be part of the restore command.
# restore -x -d -v -q -s4 -f /dev/rmt0.1 ./etc/hosts
New volume on /dev/rmt0.1:
Cluster size is 51200 bytes (100 blocks).
The volume number is 1.
The backup date is: Tue Oct 27 10:15:25 CST 1998
Files are backed up by name.
The user is root.
x 1848 ./etc/hosts
The total size is 1848 bytes.
The number of restored files is 1.
The information from the tape device during the restore operation is
displayed.
Change your directory to /etc and list the files beginning with hosts.
# cd /etc
# ls -l hosts*
-rw-rw-r-- 1 root system 1848 Sep 10 13:44 hosts
-rw-r--r-- 1 root system 2060 Aug 25 09:41 hosts.equiv
-rw-rw-r-- 1 root system 1906 Aug 25 09:41 hosts.lpd
Check if the file has been restored.
tar
The following example shows the command syntax you would use to restore
the file /etc/hosts using the tar command.
tar -x -v -f /dev/rmt0 /etc/hosts
cpio
The following shows the command syntax you would use to restore the file
/etc/hosts using the cpio command. Notice that " (quotes) are used in your file
selection.
cpio -i -c -v -d -u -m -B < /dev/rmt0 "/etc/hosts"
restore
The next two examples show the command syntax you would use to restore
the file /etc/hosts using the restore command.
The following shows how to restore the file /etc/hosts from a backup that was
made using the -i flag option during a backup by file name. Notice the -d flag
is used to restore the file:
restore -x -d -v -q -f /dev/rmt0 /etc/hosts
Chapter 8. System backup, restores, and availability 233
The following shows how to restore the file /etc/hosts when a file system
backup was used to make the backup:
restore -x -v -q -f /dev/rmt0 /etc/hosts
8.3.3 How to restore a directory
For this example, you will restore the directory /var and its contents from a tape
device /dev/rmt0.
You can use one of the following commands, depending on what command was
used to do the backup.
mksysb
There are three images (the BOS boot image, mkinsttape image, and dummy
TOC) that precede the backup files in a mksysb. Move past them using either
the mt or tctl commands with the norewind option on the tape or use the -s4
flag in the restore command.
Rewind the tape to the beginning by using the tctl command:
tctl -f /dev/rmt0 rewind
List the files on the backup media by using the restore command:
# restore -T -d -v -q -s4 -f /dev/rmt0.1
New volume on /dev/rmt0.1:
Cluster size is 51200 bytes (100 blocks).
The volume number is 1.
The backup date is: Tue Oct 27 10:15:25 CST 1998
Files are backed up by name.
The user is root.
.......... (Lines Removed)
528 ./tmp/vgdata/rootvg/hd1.map
972 ./tmp/vgdata/rootvg/hd2.map
48 ./tmp/vgdata/rootvg/hd3.map
36 ./tmp/vgdata/rootvg/hd4.map
24 ./tmp/vgdata/rootvg/hd5.map
768 ./tmp/vgdata/rootvg/hd6.map
12 ./tmp/vgdata/rootvg/hd8.map
588 ./tmp/vgdata/rootvg/hd9var.map
0 ./home
0 ./home/lost+found
0 ./home/guest
0 ./home/ftp
254 ./home/ftp/.profile
0 ./home/ftp/bin
18774 ./home/ftp/bin/ls
0 ./home/ftp/etc
0 ./home/ftp/pub
234 IBM ^ Certification Study Guide - pSeries AIX System Administration
150841 ./home/ftp/pub/aix-1-let.ps
3404039 ./home/ftp/pub/aix-2-let.ps
9210123 ./home/ftp/pub/aix-3-let.ps
4690937 ./home/ftp/pub/aix-6-let.ps
6512370 ./home/ftp/pub/aix-7-let.ps
.......... (Lines Removed)
The total size is 509575953 bytes.
The number of archived files is 37773.
This scrolls down the screen showing all of the files on the backup medium. If
you want to show only the header information you can leave out the -T and -v
flags.
Change to the /var directory and check the present working directory as in the
following:
# cd /var
# pwd
/var
List the contents of the current directory using the following command:
# ls -l
total 13
drwxrwxr-x 8 root adm 512 Oct 22 09:14 adm
drwxr-xr-x 2 bin bin 512 Aug 25 16:47 cifs
dr-xr-xr-x 3 bin bin 1024 Aug 26 13:37 ifor
drwxrwxrwx 2 root system 512 Oct 22 09:15 locks
drwx------ 2 root system 512 Aug 25 09:21 lost+found
drwxrwxrwx 2 bin bin 512 Aug 25 09:23 msgs
drwxrwxrwx 2 bin bin 512 Aug 25 09:23 news
drwxrwxrwx 2 bin bin 512 Sep 21 16:40 preserve
dr-xr-x--- 2 root system 512 Aug 25 09:39 security
drwxrwxr-x 12 bin bin 512 Sep 23 09:09 spool
drwxrwxrwt 2 bin bin 512 Oct 27 14:28 tmp
Change directory to the root directory and check the present working
directory:
# cd /
# pwd
/
Rewind the tape and start the restore of directory /var/dt. Notice the . (point)
before the directory name; this is always needed when restoring from a
mksysb backup:
# tctl -f /dev/rmt0 rewind
# restore -x -d -v -s4 -f/dev/rmt0.1 ./var/dt
New volume on /dev/rmt0.1:
Cluster size is 51200 bytes (100 blocks).
The volume number is 1.
The backup date is: Tue Oct 27 10:15:25 CST 1998
Chapter 8. System backup, restores, and availability 235
Files are backed up by name.
The user is root.
.......... (Lines Removed)
x 117 ./var/dt/Xerrors
x 5 ./var/dt/Xpid
x 44 ./var/dt/A:0-oActaa
x 44 ./var/dt/A:0-IdcsMa
x 44 ./var/dt/A:0-WqcsMa
x 44 ./var/dt/A:0-UzcsUa
x 44 ./var/dt/A:0-V7csUa
x 44 ./var/dt/A:0-kAcsUa
x 44 ./var/dt/A:0-YYcsUa
x 44 ./var/dt/A:0-Xoctia
.......... (Lines Removed)
The total size is 1065 bytes.
The number of restored files is 32.
The preceding is the information from the tape device during the restore
operation listing all the files restored.
Change your directory to /var and list the contents of the /var directory.
# cd /var
# ls -l
total 14
drwxrwxr-x 8 root adm 512 Oct 22 09:14 adm
drwxr-xr-x 2 bin bin 512 Aug 25 16:47 cifs
drwxr-xr-x 4 bin bin 512 Oct 29 10:26 dt
dr-xr-xr-x 3 bin bin 1024 Aug 26 13:37 ifor
drwxrwxrwx 2 root system 512 Oct 22 09:15 locks
drwx------ 2 root system 512 Aug 25 09:21 lost+found
drwxrwxrwx 2 bin bin 512 Aug 25 09:23 msgs
drwxrwxrwx 2 bin bin 512 Aug 25 09:23 news
drwxrwxrwx 2 bin bin 512 Sep 21 16:40 preserve
dr-xr-x--- 2 root system 512 Aug 25 09:39 security
drwxrwxr-x 12 bin bin 512 Sep 23 09:09 spool
drwxrwxrwt 2 bin bin 512 Oct 27 14:28 tmp
Verify that the directory /var/dt has been restored.
tar
The following command restores the directory and the directory contents
using the tar command:
tar -x -v -f /dev/rmt0 /var/dt
cpio
The following command restores the directory and the directory contents
using the cpio command:
cpio -i -c -v -d -u -m -B < /dev/rmt0 "/var/dt/*"
236 IBM ^ Certification Study Guide - pSeries AIX System Administration
restore
The next two commands show additional ways to restore a directory and its
contents using the restore command.
The following shows how to restore the directory from a filename backup:
restore -x -d -v -q -f /dev/rmt0 /var/dt
The following shows how to restore the directory where a file system backup
was done:
restore -x -v -q -f /dev/rmt0 /var/dt
8.3.4 Errors on restore, incorrect block size
A typical problem with moving tapes between systems is an incorrect block size.
Incorrect block sizes can cause the tape to be temporarily unreadable. For
example, a tar backup is placed on a tape with a 512 byte block size. When the
tape is placed into a system with a 2048 byte block size, and a restore is
attempted, the system displays:
# tar -tvf /dev/rmt0
tar: 0511-193 An error occurred while reading from the media.
There is an input or output error.
There are two methods to determine tape block size:
Method 1
Use the tcopy command as follows:
# tcopy /dev/rmt0
tcopy : Tape File: 1; Records: 1 to 7179 ; size:512
tcopy : Tape File: 1; End of file after :7179 records; 3675648 bytes
tcopy : Tape File: 2; Records: 1 to 2900 ; size:512
tcopy : Tape File: 2; End of file after 2900 records, 76890 bytes
...
This will give you a list of all the files found on the media with their byte count
and the block size (shown in bold) used.
Method 2
Use the dd command to read a single block from the device and find out what
block size is used for the archive:
dd if=/dev/rmt0 bs=128k count=1 | wc -c
This will return the size in bytes of the block being read.
To change the block size, use the chdev command, as follows:
# chdev -l rmt0 -a block_size=512
rmt0 changed
Chapter 8. System backup, restores, and availability 237
# tar tvf /dev/rmt0
-rw-rw-r-- 0 0 1817 Jun 09 16:24:17 2000 /etc/hosts
8.3.5 Using the rmfs command
The rmfs command removes a file system. Though it is not a normal command to
be included in a backup chapter, you can use this command once you have
restored a backup to clean up file systems that are no longer required, or
unintentionally mounted during backup time. To run the command, enter:
rmfs userfs
8.4 Cloning your system
A mksysb image enables you to clone one system image onto multiple target
systems. The target systems might not contain the same hardware devices or
adapters, require the same kernel (uniprocessor or microprocessor), or be the
same hardware platform (rs6k, rspc, or chrp) as the source system.
Use this procedure to install a mksysb backup on a target system it was not
created on. Be sure to boot from the product media appropriate for your system
and at the same maintenance level of BOS as the installed source system that
the mksysb backup was made on. For example, you can use BOS Version 4.2.1
product media with a mksysb backup from a BOS Version 4.2.1 system. This
procedure is to be used when installing a backup tape to a different system.
After booting from product media, complete the following steps when the
Welcome to the Base Operating System Installation and Maintenance screen is
displayed.
1. Select the Start Maintenance Mode for System Recovery option.
2. Select the Install from a System Backup option.
3. Select the drive containing the backup tape and insert the media for that
device. The system reads the media and begins the installation.
4. You will be prompted again for the BOS install language, and the Welcome
screen is displayed. Continue with the Prompted Installation process, as
cloning is not supported for Nonprompted Installations.
238 IBM ^ Certification Study Guide - pSeries AIX System Administration
After the mksysb backup installation completes, the installation program
automatically installs additional devices and the kernel (uniprocessor or
microprocessor) on your system using the original product media you booted
from. Information is saved in BOS installation log files. To view BOS installation
log files, enter cd /var/adm/ras and view the devinst.log file in this directory.
If the source system does not have the correct passwords and network
information, you may make modifications on the target system now. Also, some
products ship device-specific files such as graPHIGS. If your graphics adapter is
different on the target system, verify that the device-specific filesets for
graphics-related LPPs are installed.
If the system you have cloned is using OpenGL or graPHIGS, there may be some
device filesets from these LPPs that must be installed after a clone.
8.5 Creating a duplicate copy of a diskette
The dd command reads the InFile parameter or standard input, performs any
specified conversions, then copies the converted data to the OutFile parameter
or standard output.
Note:
Booting from tape product media is not supported on some rspc platform
systems. When a backup tape is created on one of these systems, the
mksysb command will display a message indicating that the system does
not support tape boot. To determine what your platform system is, enter the
following command:
bootinfo -p
or
lscfg -vp | grep Arch
If you are cloning from the product tape to restore a backup tape, create a
diskette that contains a ./bosinst.data file with
SWITCH_TO_PRODUCT_TAPE=yes in the control_flow stanza if this was
not set prior to making the mksysb.
If SWITCH_TO_PRODUCT_TAPE is set to yes, the system will prompt you
to remove the mksysb media and insert the product media after the mksysb
backup has been restored.
Chapter 8. System backup, restores, and availability 239
To make a duplicate copy of a diskette, you first use the dd command to copy the
contents of the diskette into a temporary file. Once the temporary file has been
created, use the dd command to copy the temporary file onto the /dev/fd0 device,
thus, creating a duplicate of your diskette. The following commands demonstrate
this:
# dd if=/dev/fd0 of=/tmp/ddcopy
2880+0 records in.
2880+0 records out.
# dd if=/tmp/ddcopy of=/dev/fd0
2880+0 records in.
2880+0 records out.
8.6 Duplicating a magnetic tape
The tcopy command also copies magnetic tapes. Source and target file names
are specified by the Source and Destination parameters. The tcopy command
assumes that there are two tape marks at the end of the tape, and it ends when it
finds the double file marks.
To copy from one tape device to another, enter:
# tcopy /dev/rmt0 /dev/rmt1
tcopy: Tape File: 1; Records: 1 to 74; Size: 2097152.
tcopy: Tape File: 1; Record: 75; Size 1574912.
tcopy: File: 1; End of File after: 75 Records, 156764160 Bytes.
tcopy: The end of the tape is reached.
tcopy: The total tape length is 156764160 bytes.
The duplication of the tape cartridge is now complete.
8.7 Special file notes for rmt
The purpose of the device rmt is to provide access to the sequential-access bulk
storage medium device driver.
Magnetic tapes are used primarily for backup, file archives, and other off-line
storage. Tapes are accessed through the /dev/rmt0, ..., /dev/rmt255 special files.
The r in the special file name indicates raw access through the character special
file interface. A tape device does not lend itself well to the category of a block
device. Only character interface special files are therefore provided.
240 IBM ^ Certification Study Guide - pSeries AIX System Administration
Table 8-3 is a list of the tape device special file characteristics; /dev/rmt* can be
from /dev/rmt0 to /dev/rmt255.
Table 8-3 Tape device special file characteristics
The following can be said about the characteristics shown:
The values of density setting #1 and density setting #2 come from tape drive
attributes that can be set using SMIT. Typically, density setting #1 is set to the
highest possible density for the tape drive, while density setting #2 is set to a
lower density. However, density settings are not required to follow this pattern.
The density value (bytes per inch) is ignored when using a magnetic tape
device that does not support multiple densities. For tape drives that do
support multiple densities, the density value only applies when writing to the
tape. When reading, the drive defaults to the density at which the tape is
written.
Older tape drives use a 512-byte block size. The 8 mm tape drive uses a
minimum block size of 1024 bytes. Using SMIT to lower the block size may
waste space.
8.8 High Availability Cluster Multi-Processing (HACMP)
HACMP for AIX is an application solution that can link up to eight RS/6000
servers or SP nodes into highly available clusters. With the enhanced scalability
feature, up to 16 SP nodes can be linked. Clustering servers or nodes enables
parallel access to their data, which can help provide the redundancy and fault
resilience required for business critical applications. HACMP includes graphical
user interface-based tools to help install, configure, and manage your clusters in
a highly productive manner.
Special file name Rewind-on-close Retension-on-open Bytes per inch
/dev/rmt* Yes No Density setting #1
/dev/rmt*.1 No No Density setting #1
/dev/rmt*.2 Yes Yes Density setting #1
/dev/rmt*.3 No Yes Density setting #1
/dev/rmt*.4 Yes No Density setting #2
/dev/rmt*.5 No No Density setting #2
/dev/rmt*.6 Yes Yes Density setting #2
/dev/rmt*.7 No Yes Density setting #2
Chapter 8. System backup, restores, and availability 241
HACMP is flexible in configuration and use. Uniprocessors, symmetric
multiprocessors (SMPs) and SP nodes can all participate in highly available
clusters. Micro Channel and PCI-based systems are supported under AIX. You
can mix and match system sizes and performance levels as well as network
adapters and disk subsystems to satisfy your application, network, and disk
performance needs.
HACMP clusters can be configured in several modes for different types of
processing requirements. Concurrent access mode suits environments where all
of the processors must work on the same workload and share the same data at
the same time. In a mutual takeover mode, the processors share the workload
and back each other up. Idle standby allows one node to back up any of the other
nodes in the cluster.
Whichever mode you choose, HACMP provides data access and backup plans to
help optimize application execution and scalability while helping to guard against
costly unplanned outages and down time. HACMP also enables server clusters
to be configured for application recovery/restart to provide a measure of fault
resilience for your business critical applications through redundancy.
Understanding HACMP is a lesson in fault tolerant systems. If you do not want to
commit all the resources required for an HACMP installation, you can still
eliminate many of the potential exposures for system downtime by adding
redundancy to disk drives, adapter cards, network connections, and by
implementing software RAS features, such as disk mirroring and system
monitoring as described in an HACMP installation.
242 IBM ^ Certification Study Guide - pSeries AIX System Administration
8.9 Quiz
The following certification assessment questions help verify your understanding
of the topics discussed in this chapter.
1. What is the purpose of the -i flag with the mksysb command?
A. It creates/updates the /.fsdata.
B. It reports the size of a file in bytes.
C. It creates a bootable system backup.
D. It creates or updates the /image.data file.
2. The administrator of the Widget company has decided that doing full backups
of the /apps directory each night is taking much more time than originally
assumed and that incrementals should be done during the week with one Full
backup each Saturday night. Which file
if present can be used to manage this
during the week?
A. /last_full_backup
B. /etc/last_full_backup
C. /etc/incremental_dump_dates
D. /etc/incremental_file_backup
The following are additional questions created by the authors to further test your
understanding of the topics.
1. What is the purpose of the mkszfile command?
A. It creates or updates the /image.data file.
B. It reports the size of a file in bytes.
C. It creates a bootable system backup.
D. It creates/updates the /.fsdata.
2. After creating a tar archive on a tape and verifying that the backup was
successful, a system administrator then inserts the tape into another machine
to access the data and receives the following error:
"Media Read Error - I/O Error"
Which of the following is the most likely cause of the error?
A. The blocksize or density setting is incorrect.
B. There is a lack of disk space in the root file system.
C. The tape is not read/writable.
D. There is a bad cable on the tape drive.
Chapter 8. System backup, restores, and availability 243
3. A system administrator would like to restore the third image from a mksysb
tape. To position the tape to the correct image, which of the following
commands should be run?
A. lsattr
B. tctl
C. ffwd
D. chdev
4. The finance group at the Widget Company has just approved a new financial
package that runs on an RS/6000. They will be converting their old data to the
new system. Currently, they have 10 GB of data but will be growing to 18 GB
with the new system because they want to maintain one year of history online.
The new system they have ordered is an F50 with 128 MB of RAM, an SSA
card, two 9.1 GB SSA drives, and a single FDDI card.
What would be the best addition to this system for redundancy?
1. One SSA card
2. Two 9.1 GB SSA disks
3. Error correcting RAM
4. Two additional processors
A. 3 and 1
B. 4 and 1
C. 4 and 2
D. 1 and 2
8.9.1 Answers
The following answers are for the assessment quiz questions.
1. D
2. B
The following answers are for the additional quiz questions.
1. A
2. A
3. B
4. D
244 IBM ^ Certification Study Guide - pSeries AIX System Administration
8.10 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Use mksysb to back up the volume group uservg.
2. Exclude file systems from a mksysb backup.
3. Design a sound backup schedule and strategy for your system.
4. Create a bootable system backup.
5. Retrieve a file from a mksysb, a tar backup, and a cpio backup.
6. Retrieve a directory from a mksysb, a tar backup, and a cpio backup.
7. Back up a current directory using tar.
8. What makes the mkszfile command so important?
9. Back up a single volume group.
10.Clone a system. Why use the rmfs command?
11.Make a copy of a diskette and then make a copy of a tape.
12.Position a mksysb backup at a the end of the third image.
© Copyright IBM Corp. 2001 245
Chapter 9. System Resource Controller
administration
The System Resource Controller (SRC) provides a set of commands and
subroutines to make it easier for the system manager and programmer to create
and control subsystems. A subsystem is any program or process or set of
programs or processes that is capable of operating independently or with a
controlling system. A subsystem is designed as a unit to provide a designated
function. A subserver is a program or process that belongs to a subsystem.
The SRC is designed to minimize the need for operator intervention. It provides a
mechanism to control subsystem processes using a common command line and
the C interface. This mechanism includes the following:
Consistent user interface for start, stop, and status inquiries.
Logging of the abnormal termination of subsystems.
A notification program called at the abnormal system termination of related
processes.
Tracing of a subsystem, a group of subsystems, or a subserver.
Support for control of operations on a remote system.
Refreshing of a subsystem (such as after a configuration data change).
9
246 IBM ^ Certification Study Guide - pSeries AIX System Administration
The SRC is useful if you want a common way to start, stop, and collect status
information on processes.
9.1 Starting the SRC
The System Resource Controller (SRC) is started during system initialization
with a record for the /usr/sbin/srcmstr daemon in the /etc/inittab file. The default
/etc/inittab file already contains such a record, so starting the SRC may be
unnecessary. You can, if needed, start the SRC from the command line, a
profile, or a shell script, but there are several reasons for starting it during
initialization:
Starting the SRC from the /etc/inittab file allows the init command to restart
the SRC should it stop for any reason.
The SRC is designed to simplify and reduce the amount of operator
intervention required to control subsystems. Starting the SRC from any
source other than the /etc/inittab file would be counter-productive to that goal.
The default /etc/inittab file contains a record for starting the print scheduling
subsystem (qdaemon) with the startsrc command. Typical installations have
other subsystems started with startsrc commands in the /etc/inittab file as
well. Since the startsrc command requires the SRC to be running, removing
the srcmstr daemon from the /etc/inittab file would cause these startsrc
commands to fail.
Refer to the manual page using the command man srcmstr for the configuration
requirements to support remote SRC requests.
If the /etc/inittab file does not already contain a record for the srcmstr daemon,
you can add one using the following procedure:
1. Make a record for the srcmstr daemon in the /etc/inittab file using the mkitab
command. For example, to make a record identical to the one that appears in
the default /etc/inittab file, enter:
mkitab -i fbcheck srcmstr:2:respawn:/usr/sbin/srcmstr
The -i fbcheck flag ensures that the record is inserted before all subsystems
records.
2. Tell the init command to reprocess the /etc/inittab file by entering:
telinit q
When init revisits the /etc/inittab file, it processes the newly entered record
for the srcmstr daemon and starts the SRC.
Chapter 9. System Resource Controller administration 247
9.1.1 The telinit command
The telinit command directs the actions of the init process (process ID 1) by
taking a one-character argument and signaling the init process to perform the
appropriate action. In general, the telinit command sets the system at a
specific run level. A run level is a software configuration that allows only a
selected group of processes to exist. The following arguments serve as
directives that the telinit command passes to the init process:
0-9 Tells the init process to put the system in one of the run levels 0-9.
S,s,M,m Tells the init process to enter the maintenance mode.
a,b,c Tells the init process to examine only those records in the /etc/inittab
file with a, b, or c in the run level field.
Q,q Tells the init process to re-examine the entire /etc/inittab file.
N Sends a signal that stops processes from being respawned.
9.2 Restarting the SRC
Normally, you do not need to restart srcmstr. The default record in /etc/inittab for
AIX 5L Version 5.1 is shown in Table 9-1.
Table 9-1 Default srcmstr record in the /etc/inittab file
In previous versions of AIX, srcmstr had a RunLevel value of 2.
If the srcmstr daemon terminates abnormally, the respawn action specified in the
/etc/inittab restarts the srcmstr daemon. The srcmstr daemon then determines
which SRC subsystems were active during the previous invocation. The daemon
reestablishes communication with these subsystems (if it existed previously) and
initializes a private kernel extension and the srcd daemon to monitor the
subsystem processes. Note that the process ID is changed after srcmstr is
terminated and restarted automatically as shown in Figure 9-1 on page 248.
Field Value
Identifier srcmstr
RunLevel 23456789
Action respawn
Command /usr/sbin/srcmstr
248 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 9-1 Restart of the srcmstr daemon
However, if you have edited the /etc/inittab file adding the -r or -B flag to
/usr/sbin/srcmstr, you must use the command init -q to reexamine /etc/inittab
or reboot to make the new flags effective. The -r flag prevents srcmstr from
responding to remote requests, and -B runs srcmstr in a pre-AIX Version 4.3.1
mode.
9.3 The startsrc command
The startsrc command sends the System Resource Controller (SRC) a request
to start a subsystem or a group of subsystems or to pass on a packet to the
subsystem that starts a subserver.
If a start subserver request is passed to the SRC, and the subsystem to which
the subserver belongs is not currently active, the SRC starts the subsystem and
transmits the start subserver request to the subsystem.
The flags for the startsrc command are shown in Table 9-2.
Table 9-2 Flags for the startsrc command
Flag Description Example
To start a subsystem
-a argument Specifies an argument string that
is passed to the subsystem when
the subsystem is executed.
startsrc -s srctest -a "-D
DEBUG"
This starts the srctest
subsystem with "-D DEBUG"
as two arguments to the
subsystem.
Chapter 9. System Resource Controller administration 249
-e Environment Specifies an environment string
that is placed in the subsystem
environment when the subsystem
is executed.
startsrc -s srctest -e
"TERM=dumb HOME=/tmp"
This starts the srctest
subsystem with
"TERM=dumb",
"HOME=/tmp" in its
environment to the
subsystem.
-g Group Specifies a group of subsystems
to be started.
startsrc -g nfs
This starts all the
subsystems in the
subsystem nfs group
-s Subsystem Specifies a subsystem to be
started.
startsrc -s srctest
To start either a subsystem or a subserver
-h Host Specifies the foreign host on
which this start action is
requested. The local user must be
running as root. The remote
system must be configured to
accept remote System Resource
Controller requests.
startsrc -g nfs -h itsosmp
This starts all the
subsystems in the nfs group
on the itsosmp machine.
To start a subserver
-t Ty p e Specifies that a subserver is to be
started.
startsrc -t tester
This sends a start subserver
request to the subsystem
that owns the tester
subsystem.
-o Object Specifies that a subserver object
is to be passed to the subsystem
as a character string. It is the
subsystem’s responsibility to
determine the validity of the
Object string.
startsrc -o tester -p 1234
The subserver tester is
passed as a character string
to the subsystem with a PID
of 1234.
-p SubsystemPID Specifies a particular instance of
the subsystem to which the start
subserver request is to be passed.
startsrc -t tester -p 1234
This starts the tester
subserver that belongs to
the srctest subsystem with a
subsystem PID of 1234.
Flag Description Example
250 IBM ^ Certification Study Guide - pSeries AIX System Administration
9.4 The syslogd daemon
The syslog function on AIX is provided by the syslogd daemon. The syslogd
daemon reads a datagram socket and sends each message line to a destination
described by the /etc/syslog.conf configuration file. The syslogd daemon reads
the configuration file when it is activated or when it receives a hangup signal.
9.4.1 Starting the syslogd daemon
The syslogd daemon is started during system IPL by srcmstr. The stanza in ODM
is shown in Figure 9-2.
Figure 9-2 Syslogd stanza in ODM
9.4.2 syslog configuration file
The configuration file informs the syslogd daemon where to send a system
message depending on the message's priority level and the facility that
generated it.
If you do not use the -f flag to specify an alternate configuration file, the default
configuration file /etc/syslog.conf file is used.
The syslogd daemon ignores blank lines and lines beginning with a # (pound
sign).
Chapter 9. System Resource Controller administration 251
Lines in the configuration file for the syslogd daemon contain a selector field and
an action field separated by one or more tabs.
The selector field names a facility and a priority level. Separate facility names
with a , (comma). Separate the facility and priority-level portions of the selector
field with a . (period). Separate multiple entries in the same selector field with a ;
(semicolon). To select all facilities, use an * (asterisk).
The action field identifies a destination (file, host, or user) to receive the
messages. If routed to a remote host, the remote system will handle the
message as indicated in its own configuration file. To display messages on a
user's terminal, the destination field must contain the name of a valid, logged-in
system user.
The last part of the default /etc/syslog.conf is shown in Figure 9-3.
Figure 9-3 Sample syslog configuration file
252 IBM ^ Certification Study Guide - pSeries AIX System Administration
If you decide to capture the warning messages from all users in the
/var/spool/syslog file, you should do the following:
1. Add the following line to the /etc/syslog.conf file as the last line of the file.
*.warning /var/spool/syslog
2. Create the /var/spool/syslog file.
touch /var/spool/syslog
3. Change the permission bits of /var/spool/syslog so that all users are allowed
to write warning messages to this file.
chmod 666 /var/spool/syslog
4. Refresh the syslogd daemon to make the update to the syslog configuration
file effective.
refresh -s syslogd
9.4.3 Recycling and refreshing the syslogd daemon
The syslogd daemon reads the configuration file when it is activated or when it
receives a hangup signal. A refresh keeps the current process ID and is a less
intrusive method of reading the configuration file. A recycle is useful when you
feel there is a problem with the service and a complete restart is required. You
can recycle the syslogd daemon by stopping and then starting it.
# stopsrc -s syslogd
# startsrc -s syslogd
Alternatively, you can refresh the syslogd daemon by sending a HUP signal.
ps -ef |grep syslogd
Note the PID of the syslogd process, in this example is 5682.
kill -1 5682
9.4.4 Collecting syslog data from multiple systems
The syslogd daemon logs messages received from remote hosts unless you use
the -r flag to suppress it.
In the /etc/syslog.conf of the remote hosts, instead of specifying the full path
name of a file in the destination part, put in @Host where Host is the host name
of the remote system.
Chapter 9. System Resource Controller administration 253
9.5 Refreshing a daemon
Use the refresh command to tell a System Resource Controller (SRC) resource,
such as a subsystem or a group of subsystems, to refresh itself.
The prerequisites for using the refresh command are:
The SRC must be running.
The resource you want to refresh must not use the signals communications
method.
The resource you want to refresh must be programmed to respond to the
refresh request.
The refresh command sends the System Resource Controller a subsystem
refresh request that is forwarded to the subsystem. The refresh action is
subsystem-dependent.
To start the Lotus Domino Go Webserver, use the following command:
startsrc -s httpd
To allow users to open a homepage, index.html, in a new directory, /newdir, you
have added a directory mapping in the /etc/httpd.conf file:
pass /* /newdir/*
To refresh the Web server, enter:
refresh -s httpd
After this, the users will be able to access the new homepage by entering the
following URL in their Web browser:
http://server_name[:port_number]/newdir/index.html
9.6 The cron daemon
The cron daemon runs shell commands at specified dates and times. The
following event types are scheduled by the cron daemon:
crontab command events
at command events
batch command events
sync subroutine events
ksh command events
254 IBM ^ Certification Study Guide - pSeries AIX System Administration
csh command events
The way these events are handled is specified in the /var/adm/cron/queuedefs
file.
Regularly scheduled commands can be specified according to the instructions
contained in the crontab files. You can submit your crontab file with the crontab
command. Use the at command to submit commands that are to be run only
once. Because the cron daemon never exits, it should be run only once.
The cron daemon examines crontab files and at command files only when the
cron daemon is initialized. When you make changes to the crontab files using the
crontab command, a message indicating the change is sent to the cron daemon.
This eliminates the overhead of checking for new or changed files at regularly
scheduled intervals.
When the TZ environment variable is changed, either with the chtz command, a
Web-based System Management application, or through SMIT, the cron daemon
must be restarted. This enables the cron daemon to use the correct timezone
and summer time change information for the new TZ environment variable.
The cron daemon creates a log of its activities in the /var/adm/cron/log file.
9.6.1 Crontab file record format
A crontab file contains entries for each cron job. Entries are separated by
newline characters. Each crontab file entry contains six fields separated by
spaces or tabs in the following form:
minute hour day_of_month month weekday command
These fields accept the following values:
minute 0 through 59
hour 0 through 23
day_of_month 1 through 31
month 1 through 12
weekday 0 through 6 for Sunday through Saturday
command a shell command
You must specify a value for each field. Except for the command field, these
fields can contain the following:
A number in the specified range. To run a command in May, specify 5 in the
month field.
Chapter 9. System Resource Controller administration 255
Two numbers separated by a dash to indicate an inclusive range. To run a
cron job on Tuesday through Friday, place 2-5 in the weekday field.
A list of numbers separated by commas. To run a command on the first and
last day of a month, you would specify 1,31 in the day_of_month field.
An * (asterisk), meaning all allowed values. To run a job every hour, specify
an asterisk in the hour field.
Blank lines and lines whose first non-blank character is # (number sign) are
ignored.
For example, if you have written a script fullbackup stored in the /root directory,
and you want to schedule it to run at 1 am on the 15th of every month, use the
crontab -e command to add an entry as follows:
0 1 15 * * /fullbackup
9.6.2 Allowing access to the crontab command
The /var/adm/cron/cron.allow and /var/adm/cron/cron.deny files control which
users can use the crontab command. A root user can create, edit, or delete
these files. Entries in these files are user login names with one name to a line.
If the cron.allow file exists, only users whose login names appear in it can use
the crontab command.
You can explicitly stop a user from using the crontab command by listing the
user's login name in the cron.deny file. If only the cron.deny file exists, any user
whose name does not appear in the file can use the crontab command.
A user cannot use the crontab command if one of the following is true:
The cron.allow file and the cron.deny file do not exist (allows root user only).
The cron.allow file exists but the user's login name is not listed in it.
The cron.deny file exists and the user's login name is listed in it.
If neither the cron.allow nor the cron.deny file exists, only the root user can submit
a job with the crontab command.
Note: Any character preceded by a backslash (including the %) causes
that character to be treated literally.
Note: The execute permission bit of the /fullbackup file must be on.
Note: The root user name must appear in the cron.allow file if the file exists.
256 IBM ^ Certification Study Guide - pSeries AIX System Administration
9.6.3 Housekeeping
When you have logged in as root, or used the su command to become root, the
crontab -l command shows that there are three commented entries in the
crontab file. They are:
#0 3 * * * /usr/sbin/skulker
#45 2 * * 0 /usr/lib/spell/compress
#45 23 * * * ulimit 5000; /usr/lib/smdemon.cleanu > /dev/null
These are housekeeping jobs that you can enable to clean up your system. Use
the crontab -e command to remove the # mark in column 1 to enable the jobs.
Also, you may change the time when you want the job to run. A sample crontab
file is shown in Figure 9-4.
Figure 9-4 Sample crontab file
Chapter 9. System Resource Controller administration 257
The skulker command
The skulker command is a command file for periodically purging obsolete or
unneeded files from file systems. Candidate files include files in the /tmp
directory, files older than a specified age, a.out files, core files, or ed.hup files.
The skulker command is normally invoked daily, often as part of an accounting
procedure run by the cron command during off-peak periods. Modify the skulker
command to suit local needs following the patterns shown in the distributed
version. System users should be made aware of the criteria for automatic file
removal.
The find command and the xargs command form a powerful combination for use
in the skulker command. Most file selection criteria can be expressed
conveniently with find expressions. The resulting file list can be segmented and
inserted into rm commands using the xargs command to reduce the overhead
that would result if each file were deleted with a separate command.
To enable the skulker command, you should use the crontab -e command to
remove the comment statement by deleting the # (pound sign) character from the
beginning of the /usr/sbin/skulker line in the /var/spool/cron/crontabs/root file.
The /usr/lib/spell/compress command
This is not the AIX compress command. The /usr/lib/spell/compress command
is a shell script to compress the spell program log.
To enable the /usr/lib/spell/compress command, you should use the crontab
-e command to remove the comment statement by deleting the # (pound sign)
character from the beginning of the /usr/lib/spell/compress line in the
/var/spool/cron/crontabs/root file.
The script is shown in Figure 9-5 on page 258.
Note: Because the skulker command is run by a root user and its whole
purpose is to remove files, it has the potential for unexpected results.
Before installing a new skulker command, test any additions to its file
removal criteria by running the additions manually using the xargs -p
command. After you have verified that the new skulker command removes
only the files you want removed, you can install it.
258 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 9-5 /usr/lib/spell/compress script
This script removes all duplicated words in the /usr/lib/spell/spellhist file. This file
is updated when the users invoke the spell command.
The /usr/lib/smdemon.cleanu command
The smdemon.cleanu command is a shell procedure that cleans up the sendmail
command queue and maintains the /var/spool/mqueue/log file.
To enable the smdemon.cleanu command, you must remove the comment
statement by deleting the # (pound sign) character from the beginning of the
smdemon.cleanu line in the /var/spool/cron/crontabs/root file. If the
/var/spool/mqueue directory does not exist, do not change the
/var/spool/cron/crontabs/root file.
Be careful that the average size of a log file for each smdemon.cleanu session
multiplied by the number of log files does not use more space than you need.
You can arrange the number of log files to suit your needs.
Note: The smdemon.cleanu command is not usually entered on the
command line. The command is executed by the cron daemon.
Chapter 9. System Resource Controller administration 259
9.7 Quiz
The following certification assessment question helps verify your understanding
of the topics discussed in this chapter.
1. The system administrator would like to log messages related to user login
failures to a file. How could this be accomplished?
A. Issue the command: alog -f /etc/security/failedlogin -q
B. Modify the /etc/security/login to add an auth_method for logging.
C. Add a line to the /etc/syslog.conf file to capture this information.
D. Set log=true in the default stanza in the /etc/security/user file.
The following are additional questions created by the authors to further test your
understanding of the topics.
1. A system administrator would like to collect a log file of su activity on all hosts
across a network. The central logfile will reside on host mars. The syslog
daemon is already operational on host mars. Which of the following is the first
step in accomplishing this task?
A. Edit the /var/adm/sulog file on all hosts except mars adding the line:
remote:mars
B. Edit the /etc/syslog.conf file on all hosts except mars adding the line:
auth.debug @mars
C. Edit the /var/adm/syslog file on all hosts except mars adding the line:
sulog = mars
D. Edit the /etc/security/user file on all hosts except mars adding the
following line to the default stanza:
sulog = mars
2. An overwrite installation has just been completed to bring the machine up to
the latest AIX version. Which of the following is the next step to take in order
to enable operation of skulker?
A. Run the command: startsrc -s skulker
B. Run the command: chitab "skulker:2:wait:/etc/rc.skulker"
C. Remove the comment from the skulker entry of the root crontab
D. Remove the comment from the skulker entry in the inetd.conf and refresh
inetd.
260 IBM ^ Certification Study Guide - pSeries AIX System Administration
9.7.1 Answers
The following answer is for the assessment quiz questions.
1. C
The following answers are for the additional quiz questions.
1. B
2. C
9.8 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. What is needed to restart the SRC in AIX Version 4.3.2 or AIX Version 4.2.1?
Is a reboot needed? Can it be done by refresh or other commands?
2. What is the startsrc command and what are the use of its major flags?
3. Start the syslog and examine the results.
4. What is the syslog configuration file? What should be done to refresh the
daemon?
5. Collect syslog data from many systems.
6. Refresh the syslogd daemon to pick up modifications.
7. Refresh a daemon.
8. Explain the configuration file for cron jobs.
9. Enable the skulker, or other commented daemons.
© Copyright IBM Corp. 2001 261
Chapter 10. Network administration
A network is the combination of two or more computers and the connecting links
between them. A physical network is the hardware (equipment, such as adapter
cards, cables, and concentrators) that makes up the network. The software and
the conceptual model make up the logical network.
You will find important aspects of administrating TCP/IP on the system in this
section, including IP addressing, network daemons, and basic network security.
Note that this does not present the full scope of network administration.
10
262 IBM ^ Certification Study Guide - pSeries AIX System Administration
10.1 Network startup at boot time
At IPL time, the /init process will run /etc/rc.tcpip after starting the SRC. The
/etc/rc.tcpip file is a shell script that, when executed, uses SRC commands to
initialize selected daemons. It can also be executed at any time from the
command line.
Most of the daemons that can be initialized by the rc.tcpip file are specific to
TCP/IP. These daemons are:
inetd (started by default)
gated
routed
named
timed
rwhod
There are also daemons specific to the base operating system or to other
applications that can be started through the rc.tcpip file. These daemons are:
lpd
portmap
sendmail
syslogd (started by default)
10.2 Stopping and restarting TCP/IP daemons
The subsystems started from rc.tcpip can be stopped using the stopsrc
command and restarted using the startsrc command.
10.2.1 Stopping TCP/IP daemons using the /etc/tcp.clean command
The script /etc/tcp.clean can be used to stop TCP/IP daemons. It will stop the
following daemons and remove the /etc/locks/lpd TCP/IP lock files:
ndpd-host
lpd
Note: Running the gated and routed daemons at the same time on a host
may cause unpredictable results.
Chapter 10. Network administration 263
routed
gated
sendmail
inetd
named
timed
rwhod
iptrace
snmpd
rshd
rlogind
telnetd
syslogd
Note that the script /etc/tcp.clean does not stop the portmap and nfsd daemons.
If you want to stop the portmap and the nfsd daemons, use the stopsrc -s
portmap and the stopsrc -s nfsd commands. The execution bit of this
/etc/tcp.clean file is not on by default. You will have to invoke it by issuing:
sh /etc/tcp.clean
10.2.2 Restarting TCP/IP daemons
The /etc/rc.tcpip script can be used to restart TCP/IP daemons. Alternatively, you
can use the startsrc -s command to start individual TCP/IP daemons.
10.3 System boot without starting rc.tcpip
Connections using TCP/IP are often peer-to-peer. There are no master/slave
relations. The applications, however, use a client/server model for
communications.
Note: Do not restart TCP/IP daemons using the command:
startsrc -g tcpip
It will start all subsystems defined in the ODM for the tcpip group, which
includes both routed and gated.
264 IBM ^ Certification Study Guide - pSeries AIX System Administration
Removing the rc.tcpip entry in /etc/inittab means that you are not starting any
server applications during IPL.
Without the server applications started, you will not be able to telnet or ftp to
this machine from another host.
However, as long as you have not brought down the network interface, you can
still utilize the client network services. You can still ping other hosts, you can still
telnet to other hosts, and you can still ftp to other hosts.
The ping command sends an Internet Control Message Protocol (ICMP)
ECHO_REQUEST to obtain an ICMP ECHO_RESPONSE from a host and does
not need a server application. Therefore, even without starting any server
application, the machine will still respond to a ping request from other hosts.
10.4 The inetd daemon
The /usr/sbin/inetd daemon provides Internet service management for a network.
This daemon reduces system load by invoking other daemons only when they
are needed and by providing several simple Internet services internally without
invoking other daemons.
10.4.1 Starting and refreshing inetd
When the daemon starts, it reads its configuration information from the file
specified in the Configuration File parameter. If the parameter is not specified,
the inetd daemon reads its configuration information from the /etc/inetd.conf file.
Once started, the inetd daemon listens for connections on certain Internet
sockets in the /etc/inetd.conf and either handles the service request itself or
invokes the appropriate server once a request on one of these sockets is
received.
The /etc/inetd.conf file can be updated by using the System Management
Interface Tool (SMIT), the System Resource Controller (SRC), or by editing the
/etc/inetd.conf.
Note: If you have a graphic console, make sure you also remove the rc.dt
and rc.tcpip entries in the /etc/inittab file. Otherwise, your console will hang
when you login. Unless you have an ASCII terminal connected to the serial
port, there is no way you can recover since you will not be able to
communicate with the machine through the telnet or rlogin commands
with no TCP/IP server application started.
Chapter 10. Network administration 265
If you change the /etc/inetd.conf using SMIT, then the inetd daemon will be
refreshed automatically and will read the new /etc/inetd.conf file. If you change
the file using an editor, run the refresh -s inetd or kill -1 InetdPID
commands to inform the inetd daemon of the changes to its configuration file.
You will not receive a message if you use the kill -1 command as shown in
Figure 10-1.
Figure 10-1 Refreshing the inetd daemon using refresh or kill
10.4.2 Subservers controlled by inetd
The inetd daemon is a subsystem that controls the following daemons
(subservers):
comsat daemon
ftpd daemon
fingerd daemon
rlogind daemon
rexecd daemon
rshd daemon
talkd daemon
telnetd daemon
tftpd daemon
uucpd daemon
The ftpd, rlogind, rexecd, rshd, talkd, telnetd, and uucpd daemons are started by
default. The tftpd, fingerd, and comsat daemons are not started by default.
To start any one of them, remove the pound (#) sign in column one of the
respective entry in the /etc/inetd.conf file. You can check the details of subservers
started in inetd by using the lssrc -ls command, as shown in Figure 10-2 on
page 266.
266 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 10-2 Subservers started in inetd
10.4.3 The /etc/services file
The /etc/services file contains information about the known services used in the
DARPA Internet network by inetd. Each service listed in /etc/services runs on a
specific port number for communications, in a specific format, such as TCP or
UDP.
Each service is listed on a single line corresponding to the form:
ServiceName PortNumber/ProtocolName Aliases
A sample section from /etc/services may look like the following:
echo 7/tcp
echo 7/udp
discard 9/tcp sink null
Chapter 10. Network administration 267
discard 9/udp sink null
daytime 13/tcp
daytime 13/udp
chargen 19/tcp ttytst source
chargen 19/udp ttytst source
ftp 21/tcp
time 37/tcp timeserver
time 37/udp timeserver
If you edit the /etc/services file, run the refresh -s inetd command, in order for
your changes to be used.
10.4.4 Stopping inetd
Use the command stopsrc -s inetd to stop the inetd daemon as shown in
Figure 10-3.
Figure 10-3 Stopping inetd
When the inetd daemon is stopped, the previously started subserver processes
are not affected. However, new service requests for the subservers can no longer
be satisfied. If you try to telnet or ftp to the server with inetd down, you will see
messages as shown in Figure 10-4.
Figure 10-4 Telnet and FTP when inetd on sv1166f is down
In other words, existing sessions are not affected when the inetd daemon is
stopped, but no new telnet and ftp sessions can be established without first
restarting the inetd daemon.
268 IBM ^ Certification Study Guide - pSeries AIX System Administration
10.5 The portmap daemon
The portmap daemon converts remote procedure call (RPC) program numbers
into Internet port numbers.
When an RPC server starts up, it registers with the portmap daemon. The server
tells the daemon which port number it is listening to and which RPC program
numbers it serves. Thus, the portmap daemon knows the location of every
registered port on the host and which programs are available on each of these
ports.
A client consults the portmap daemon only once for each program the client tries
to call. The portmap daemon tells the client which port to send the call to. The
client stores this information for future reference.
Since standard RPC servers are normally started by the inetd daemon, the
portmap daemon must be started before the inetd daemon is invoked.
10.6 Internet addressing
If you want your machines to communicate with each other across the TCP/IP
network, you must give them unique IP addresses. Each host is assigned a
unique 32-bit logical address (in the case of IPv4) that is divided into two main
parts: the network number and the host number. The network number identifies a
logical network to which the host belongs and must be the same across the
subnet. The host number identifies a host on the specific logical network.
10.6.1 IP address format
The IP address is the 32-bit address, grouped eight bits at a time, separated by
dots and represented in decimal format called dotted decimal notation. Each bit
in the octet has a binary weight (128, 64, 32,16, 8, 4, 2, 1). The minimum value
for an octet is 0, and the maximum value for an octet is 255. Figure 10-5 on
page 269 illustrates the basic format of an IP address.
Note: If the portmap daemon is stopped or comes to an abnormal end, all
RPC servers on the host must be restarted.
The nfsd is a common RPC server.
Chapter 10. Network administration 269
Figure 10-5 IP address format
10.6.2 Binary to decimal conversion
The decimal value of the bits ranges from high to low with the left-most bit in
every byte having the highest value of 128. To convert from binary value to
decimal value, add decimal values on the position where the bits have value of 1.
An example is shown in Figure 10-6.
Figure 10-6 Binary to decimal conversion
Host
8 bits 8 bits 8 bits 8 bits
20019 177153 ...
32 bits
Network
1286432168421
11111111
10011001
Binary
12800168001
Binary
270 IBM ^ Certification Study Guide - pSeries AIX System Administration
To convert numbers to and from binary format, you can use the bc command. To
make the conversion of value 195 to binary format, enter:
# bc
obase=2
195
11000011
To convert the binary number 11001100 to a decimal format, enter:
# bc
ibase=2
11001100
204
10.6.3 Internet address classes
IP addressing supports five different address classes: A, B, C, D, and E. Classes
A, B, and C are available for commercial use. You can determine the network
class of an IP address by checking the bits in the first octet of a network address.
By converting all of the bits of an IP address to binary format and calculating the
number of hosts and networks available, you will receive data similar to that
shown in Figure 10-7.
Figure 10-7 IP address classes
CLASS A
CLASS B
CLASS C
CLASS D
O
1O
11O
111O
7 bits
14 bits
21 bits
28 bits
8 bits
16 bits
24 bits
Multicast address
Network
address
Network
address
Network
address
Host
address
Host
address
Host
address
Chapter 10. Network administration 271
To determine the class of an IP address, refer to Table 10-1 on page 271.
Table 10-1 IP address classes
For example, in the IP address 195.116.119.2, the first octet is 195. Because 195
falls between 192 and 223, 195.116.119.2 is a class C address.
Class A, B, and C addresses also provide address ranges that are useful to
define a private network without INTERNIC authorization. A private network can
have the following address ranges:
Class A 10.0.0.0 to 10.255.255.255
Class B 172.16.0.0 to 172.31.255.255
Class C 192.168.0.0 to 192.168.255.255
10.6.4 Special Internet addresses
There are a few IP addresses that cannot be used as host addresses. Those
addresses are used for special occasions.
The loopback interface allows a client and server on the same host to
communicate with each other using TCP/IP. The network class A with network
address 127 is reserved for the loopback interface lo0. AIX assigns the IP
address 127.0.0.1 to this interface and assigns it the name localhost. To check
attributes of any interface use the ifconfig or lsattr commands as follows:
# ifconfig lo0
lo0:
flags=e08084b<UP,BROADCAST,LOOPBACK,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64BIT>
IP
address
class
Format First
octet
Address range Number
bits
network /
host
Number
of hosts
A
N.H.H.H 0 1.0.0.0
127.0.0.0
7 / 24 2
24
- 2
B
N.N.H.H 10 128.1.0.0
191.254.0.0
14 / 16 2
16
- 2
C
N.N.N.H 110 192.0.1.0
223.255.254.0
22 / 8 2
8
- 2
D
- 1110 224.0.0.0
239.255.255.255
--
N - Network number
H - Host number
272 IBM ^ Certification Study Guide - pSeries AIX System Administration
inet 127.0.0.1 netmask 0xff000000 broadcast 127.255.255.255
inet6 ::1/0
# lsattr -El lo0
netaddr 127.0.0.1 Internet Address True
state up Current Interface Status True
netmask Subnet Mask True
mtu 16896 Maximum IP Packet Size for This Device True
netaddr6 ::1 N/A True
prefixlen Subnet Mask True
The network address is an IP address with all host address bits set to 0. If you
have the IP address 195.116.119.2, the network address for this will be
195.116.119.0. This type of address is used in the routing table as the network
destination address. An example routing table is shown in the following (0 is
omitted in the routing tables).
# netstat -nr
Routing tables
Destination Gateway Flags Refs Use If PMTU Exp Groups
Route Tree for Protocol Family 2 (Internet):
default 9.3.240.1 UGc 0 0 tr0 - -
9.3.240/24 9.3.240.58 U 30 130787 tr0 - -
127/8 127.0.0.1 U 54 1300 lo0 - -
195.116.119/24 195.116.119.2 U 0 2 en0 - -
The limited broadcast address is 255.255.255.255 (an address with all host
address and network address bits set to 1). This can be used as the destination
address for all hosts regardless of their network number. Routers never forward a
limited broadcast; it only appears on the local cable.
The directed broadcast address is an IP address, with all the host address bits
set to 1. It is used to simultaneously address all hosts within the same network.
For example, consider an IP address 195.116.119.2; because it is class C
address, the network address for this address is 195.116.119. Therefore, the
directed broadcast for this network will be 195.116.119.255. To check the
broadcast setting for interface en0, enter:
# ifconfig en0
en0:
flags=e080863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64BIT>
inet 195.116.119.2 netmask 0xffffff00 broadcast 195.116.119.255
The last column of Table 10-1 on page 271 shows the number of hosts in the
appropriate network class. Notice that the two hosts were subtracted. This was
done so that one address is reserved for the broadcast address, and one
address is reserved for the network address.
Chapter 10. Network administration 273
10.6.5 Subnetting
Subnet addressing allows an autonomous network made up of multiple systems
to share the same Internet address class. The subnetwork capability of TCP/IP
also makes it possible to divide a single network into multiple logical networks
(subnets). This makes sense for class A and class B addresses, since attaching
thousands of hosts to a single network is impossible.
A standard IP address has two fields (see “IP address format” on page 268): a
network address and a host address. A subnet address is created by borrowing
bits from the host field and designating them as the subnet field. The number of
borrowed subnet bits varies and it depends of the chosen subnet mask.
Figure 10-8 shows how bits are borrowed from the host address field to create
the subnet address field and how the subnet mask works.
Figure 10-8 Subnetting example
When deciding how to partition the host address into the subnet address and
host address, you should consider the number of subnets and the number of
hosts on those subnets.
You have great flexibility when assigning subnet addresses and host addresses.
The bits of the host address can be divided according to the needs and potential
growth of the organization and its network structure. The only restrictions are:
The network address is constant for all its subnets.
The subnet address is constant throughout the physical network.
The host address is a field that is normally at least 2-bits wide.
network address
8 bits
host address
24 bits
network address
8 bits
00001001
011011000000011 11 110000
subnet address host address
11111111
0000000011111111 11 000000
Address
Subnet
mask
255 255
.
192.
.
0
274 IBM ^ Certification Study Guide - pSeries AIX System Administration
If the width of the subnet address field is 0, the network is not organized into
subnets, and addressing to the network is performed using the Internet network
address as mentioned in Section 10.6.1, “IP address format” on page 268.
10.6.6 Subnet masks
The subnet mask tells the system what the subnet partitioning scheme is. This bit
mask consists of the network address portion and subnet address portion of the
IP address.
When a host sends a message to a destination, the system must determine
whether the destination is on the same network as the source or if the destination
must be reached through a gateway. The system compares the destination
address to the host address using the subnet mask. If the destination is not on
the local network, the system sends the packet to a gateway. The gateway
performs the same comparison to see if the destination address is on a network it
can reach locally.
Table 10-2 shows how to calculate the subnet mask from binary format to the
dotted decimal notation.
Table 10-2 Subnet mask calculation
Note: It is generally desirable for the subnet bits to be contiguous and
located as the most significant bits of the host address.
Bits of octet Mask
1286432168421
10000000128
11000000192
11100000224
11110000240
11111000248
11111100252
11111110254
11111111255
Chapter 10. Network administration 275
A subnet mask is 32 bits long. A bit set to 1 in the subnet mask indicates that bit
position is part of the network address portion of the IP address. A bit set to 0 in
the subnet mask indicates that bit position is part of the host address portion of
the IP address.
There are default subnet mask sets (Figure 10-9) for each network class
address. Using an address with a default subnet mask for an address class
indicates that subnets are not set up for the network.
Figure 10-9 Default subnet mask for network classes
The class B address subnetting example
The default subnet mask for a class B address that has no subnetting is
255.255.0.0, while the subnet mask for a class B address 172.16.0.0 that
specifies 3 bits of subnetting is 255.255.224.0. The reason for this is that 3 bits of
subnetting give 2
3
- 2= 6 (1 for the network address and 1 for the broadcast
address) subnets possible. You have 5 bits from the 3rd octet and 8 bits from the
last octet forming a total of 13 bits for the hosts address. This gives you 2
13
- 2 =
8190 hosts per subnet. Figure 10-10 on page 276 shows a subnetting scenario
for this address.
11111111 00000000 00000000 00000000
11111111 11111111 00000000 00000000
11111111 11111111 11111111 00000000
Binary
Binary
Binary
Dotted decimal
255.0.0.0
255.255.0.0
255.255.255.0
Dotted decimal
Dotted decimal
class C class B class A
276 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 10-10 Subnetting scenario
Table 10-3 shows the subnet mask, the number of subnets and the number of
hosts based on the number of bits for the subnet for network class B.
Table 10-3 Class B subnetting reference chart
Numbers of bits
for subnet
Subnet mask Number of
subnets
Number of hosts
2 255.255.192.0 2 16382
3 255.255.224.0 6 8190
4 255.255.240.0 14 4094
5 255.255.248.0 30 2046
6 255.255.252.0 62 1022
7 255.255.254.0 126 510
8 255.255.255.0 254 254
11111111 11111111 11100000 00000000
10101100 00010000 00100000 00000000
10101100 00010000 00100000 00000001
11111111 00010000 00111111 11111111
10101100 00010000 01000000 00000000
10101100 00010000 01000000 00000001
255 255 224 0
172 16 32 0
172 16 32 1
172 16 64 0
172 16 64 1
172 16 63 255
10101100 00010000 01011111 11111111
172 16 95 255
Subnet mask
255.255.224.0
1st subnet
1st host in this
subnet
Subnet
broadcast
2nd subnet
1st host in this
subnet
Subnet
broadcast
Chapter 10. Network administration 277
The class C address subnetting example
The subnet mask for a class C address 192.168.2.0 that specifies 5 bits of
subnetting is 255.255.255.248. With 5 bits available for subnetting, 2
5
- 2 = 30
subnets possible. Now you have 3 bits left for the hosts part and it gives 2
3
- 2 = 6
hosts per subnet. Table 10-4 shows the number of hosts, number of subnets, and
subnet mask based on the numbers of bits for subnet.
Table 10-4 Class C subnetting reference chart
10.7 Host name resolution
TCP/IP provides a naming system that supports both flat and hierarchical
network organizations so that users can use meaningful, easily remembered
names instead of Internet addresses.
In flat TCP/IP networks, each machine on the network has a file (/etc/hosts)
containing the name-to-Internet-address mapping information for every host on
the network.
9 255.255.255.128 510 126
10 255.255.255.192 1022 62
11 255.255.255.224 2046 30
12 255.255.255.240 4096 14
13 255.255.255.248 8190 6
14 255.255.255.252 16382 2
Number of bits
for subnet
Subnet mask Number of
subnets
Number of hosts
2 255.255.255.192 2 62
3 255.255.255.224 6 30
4 255.255.255.240 14 14
5 255.255.255.248 30 6
6 255.255.255.252 62 2
Numbers of bits
for subnet
Subnet mask Number of
subnets
Number of hosts
278 IBM ^ Certification Study Guide - pSeries AIX System Administration
When TCP/IP networks become very large, as on the Internet, naming is divided
hierarchically. Typically, the divisions follow the network's organization. In TCP/IP,
hierarchical naming is known as the domain name system (DNS) and uses the
DOMAIN protocol. The DOMAIN protocol is implemented by the named daemon
in TCP/IP.
The default order in resolving host names is:
1. BIND/DNS (named)
2. Network Information Service (NIS)
3. Local /etc/hosts file
The default order can be overwritten by creating the configuration file,
/etc/netsvc.conf and specifying the desired order. Both the default and
/etc/netsvc.conf can be overwritten with the environment variable NSORDER.
You can override the default order by creating the /etc/netsvc.conf file with an
entry. If /etc/netsvc.conf does not exist, the default will be as though you made
the following entry:
hosts = bind,nis,local
You can override the default or the configuration file order by changing the
NSORDER environment variable. If it is not set, the default will be as though you
issued the command:
export NSORDER=bind,nis,local
10.7.1 The /etc/resolv.conf file
The /etc/resolv.conf file defines Domain Name Protocol (DOMAIN) name-server
information for local resolver routines. If the /etc/resolv.conf file does not exist,
then BIND/DNS is considered to be not set up or running and, therefore, not
available. The system will attempt name resolution using the default paths, the
/etc/netsvc.conf file, or the NSORDER environment variable.
A sample /etc/resolv.conf file is shown in Figure 10-11.
Figure 10-11 Sample /etc/resolv.conf file
Chapter 10. Network administration 279
In this case, there is only one name server defined, with an address of 9.3.1.74.
The system will query this domain name server for name resolution. The default
domain name to append to names that do not end with a . (period) is
itsc.austin.ibm.com. The search entry defines the list of domains to search when
resolving a name; in the above example, they are itsc.austin.ibm.com and
austin.ibm.com.
10.7.2 Related problems with /etc/resolv.conf
When you have problems resolving a host name, and you are using a name
server, you should:
1. Verify that you have a /etc/resolv.conf file specifying the correct domain name
and Internet address of a name server. If you try to access a host by name
with an incorrect entry in /etc/resolv.conf, and if the host is also not defined in
/etc/hosts, you will get an error message, as shown in the following example:
# ping olympus
0821-062 ping: host name olympus NOT FOUND
2. If /etc/resolv.conf contains the correct data, verify that the host acting as the
local name server is up by issuing the ping command with the IP address of
the name server found in the /etc/resolv.conf file.
3. If the local name server is up, verify that the named daemon on that local
system is active by issuing the lssrc -s named command on that host.
4. If you are running the syslogd daemon, there could be error messages
logged. The output for these messages is defined in the /etc/syslog.conf file.
10.7.3 The nslookup command
The nslookup command queries domain name servers for information about
various hosts and domains. The nslookup command is useful for determining
host names of servers of systems on the Internet by IP address, host name, or
domain. The nslookup command can be run as follows:
# nslookup [IPAddress | HostName]
For example, to determine the host name of the system with the IP address of
207.25.253.26, you would enter:
# nslookup 207.25.253.26
Server: dhcp001.itsc.austin.ibm.com
Address: 9.3.240.2
Name: service.boulder.ibm.com
Address: 207.25.253.26
280 IBM ^ Certification Study Guide - pSeries AIX System Administration
In this example, the host name of the system with the IP address of
207.25.253.26 is service.boulder.ibm.com.
The nslookup command can also determine IP addresses of systems by host
name. For example, to display the IP address of service.software.ibm.com, you
would enter:
# nslookup service.software.ibm.com
Server: dhcp001.itsc.austin.ibm.com
Address: 9.3.240.2
Non-authoritative answer:
Name: service.boulder.ibm.com
Address: 207.25.253.26
Aliases: service.software.ibm.com
In this example, the IP address of service.software.ibm.com is 207.25.253.26.
The nslookup output also shows that service.software.ibm.com is an alias for
service.boulder.ibm.com.
10.8 New adapter considerations
Changing network adapters in a machine may require additional configuration
steps after the basic hardware installation. Consider the following tasks as the
additional steps required to configure a new adapter.
1. If you missed the informational messages from the cfgmgr command invoked
during system boot, you should invoke the command again to check if the
required device-dependent software is missing.
2. Install the required device software, if needed using the smitty devices
command.
3. Invoke the diag -a command to confirm that the new adapter resource is
added in the hardware configuration.
4. Rerun cfgmgr.
5. Ensure that the adapter is available on the system by invoking the lsdev -Cl
command on the adapter. For example:
# lsdev -Cl ent0
6. Obtain the IP address and netmask from your network architect.
7. Configure the network interface using the SMIT fast path smit inet. Do not
use smit mktcpip. It is only used for configuring TCP/IP for the first time.
8. Enable IP forwarding if the machine is connected to two networks.
9. Add a route to those systems that need access from any private networks.
Chapter 10. Network administration 281
10.8.1 Configuring a network adapter using SMIT
To change advanced features of network adapters, including ring speed, duplex
settings, and queue sizes for transmitting and receiving information, use the
SMIT fast path smit chgenet for Ethernet adapters, and smit chgtok for token
ring adapters. A sample screen of smit chgenet is shown in Figure 10-12.
Figure 10-12 Change/Show Characteristics of an Ethernet Adapter menu
10.8.2 Configuring a network interface using SMIT
The SMIT fast path command used to configure TCP/IP is smit tcpip. You can
configure a network interface using the fast path smit inet. For these examples,
we will be using an Ethernet interface, en0.
1. Check whether the en0 interface exists by selecting List All Network
Interfaces. If en0 does not exist, select Add a Network Interface, and then
select Add a Standard Ethernet Network Interface. You should see a panel
similar to in Figure 10-13 on page 282.
282 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 10-13 Available Network Interfaces submenu
2. Press Enter to select en0 and fill in the following dialog screen.
Choose the interface that you need to configure and fill in the necessary
information. A sample screen is shown in Figure 10-14 on page 283.
Chapter 10. Network administration 283
Figure 10-14 Add a Standard Ethernet Network Interface menu
3. On completion of adding the standard Ethernet network interface, you should
see the message en0 Available.
4. If en0 already exists, select Change/Show Characteristics of a Network
Interface. The SMIT fast path is smit chinet. A sample screen is shown in
Figure 10-15 on page 284.
284 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 10-15 Change/Show a Standard Ethernet Interface menu
5. On completion of changing the standard Ethernet interface, you should see a
message that the en0 interface has been changed.
10.9 Enabling IP forwarding
To allow other systems to access a different network through a machine
containing two network adapters, you must enable IP forwarding on that
machine. The system will now act as a gateway between network A and network
B.
IP forwarding is a runtime attribute. The default value of 0 (zero) prevents
forwarding of IP packets when they are not for the local system. A value of 1
(one) enables forwarding. Enable IP forwarding using the command:
no -o ipforwarding=1
This setting will be lost following a system reboot.
Chapter 10. Network administration 285
10.10 Adding network routes
For those systems that need to access a private network, use the SMIT fast path
smit route or smit mkroute to add a route to the private network through the
gateway between two networks. A sample of smit mkroute is shown in
Figure 10-16.
Figure 10-16 Adding a Static Route menu
Instead of using SMIT, you can also use the command:
route add -net 192.168.1 -netmask 255.255.255.0 9.3.1.124
The procedure, shown in Figure 10-17 on page 286, illustrates:
A host cannot access the IP addresses 192.168.1.1 and 192.168.1.2.
A route is added using the route add command specifying that 9.3.1.124
should be used as the gateway to the network 192.168.1.
The traceroute command shows the route taken to reach both 192.168.1.1
and 192.168.1.2.
286 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 10-17 Adding a route using the route add command
10.11 Changing IP addresses using SMIT
If you are moving your machine from one network segment to another, and need
to change IP addresses, use smit mktcpip the same way as the first time you
configured TCP/IP. You may need to change the host name, IP address, and the
default gateway address. A sample screen is shown in Figure 10-18 on
page 287.
Chapter 10. Network administration 287
Figure 10-18 Minimum Configuration & Startup menu
If you are not moving across network segments, and simply want to change the
IP address, you can change the field START Now shown in Figure 10-18 to yes.
This will start the TCP/IP daemons automatically or refresh them if they are
already started.
10.12 The ifconfig command
The ifconfig command can allow you to configure and modify properties of
network interfaces directly, without the use of SMIT. Often, administrators find
this easier than using the SMIT panels for network administration.
The syntax of the ifconfig command for configuring and modifying network
interfaces is as follows:
ifconfig Interface [ AddressFamily [ Address [ DestinationAddress ] ]
[Parameters... ] ]
Note: Do not perform this task in a Telnet session, as you will lose your
connection when the change is made.
288 IBM ^ Certification Study Guide - pSeries AIX System Administration
There are three address families that can be used with the ifconfig command:
inet The default dotted decimal notation for a system that is part of the
DARPA-Internet. This is the address family that ifconfig uses by default.
inet6 The default dotted decimal notation for a system that is part of the
DARPA-Internet running IPv6.
ns The default dotted hexadecimal notation for a system that is part of a
Xerox Network Systems family.
Table 10-5 is a list of common command parameters and their functions for the
ifconfig command.
Table 10-5 Common parameters for ifconfig
10.12.1 Identifying network interfaces
Before you use the ifconfig command to perform administration on network
interfaces, it is helpful to identify all interfaces on your server. There are two ways
to identify network interfaces on your server. The first command that you can run
is:
# lsdev -Cc if
This will produce a simple list of all interfaces on the system, whether they are
being actively used by the system or not. For example:
# lsdev -Cc if
en0 Defined 10-80 Standard Ethernet Network Interface
en1 Defined 20-60 Standard Ethernet Network Interface
et0 Defined 10-80 IEEE 802.3 Ethernet Network Interface
et1 Defined 20-60 IEEE 802.3 Ethernet Network Interface
lo0 Available Loopback Network Interface
Parameter Description
alias Establishes an additional network address for the interface.
delete Removes the specified network address from the interface.
detach Removes an interface from the network interface list.
down Marks an interface as inactive (down), which keeps the system from
trying to transmit messages through that interface.
mtu Value Sets the maximum IP packet size to Value bytes, (maximum
transmission unit), ranging from 60 to 65535.
netmask Mask Specifies how much of the address to reserve for subdividing
networks into subnetworks.
up Marks an interface as active (up).
Chapter 10. Network administration 289
tr0 Available 10-68 Token Ring Network Interface
The second command that you can run is:
# ifconfig -a
This will produce a list of all network interfaces on the system that have IP
addresses assigned and are actively being used by the system. For example:
# ifconfig -a
tr0: flags=e0a0043<UP,BROADCAST,RUNNING,ALLCAST,MULTICAST,GROUPRT,64BIT>
inet 10.1.2.2 netmask 0xffffff00 broadcast 10.1.2.255
lo0:
flags=e08084b<UP,BROADCAST,LOOPBACK,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64BIT
>
inet 127.0.0.1 netmask 0xff000000 broadcast 127.255.255.255
inet6 ::1/0
To get information about one specific network interface, including state, IP
address, and netmask, run the command:
# ifconfig Interface
To get information about tr0, for example, run the command:
# ifconfig tr0
tr0: flags=e0a0043<UP,BROADCAST,RUNNING,ALLCAST,MULTICAST,GROUPRT,64BIT>
inet 10.1.2.2 netmask 0xffffff00 broadcast 10.1.2.255
10.12.2 Activating a network interface
Before messages can be transmitted through a network interface, the interface
must be placed in the up or active state. To activate an interface using ifconfig,
run the command:
# ifconfig Interface [Address] [netmask Netmask] up
To activate a network interface using ifconfig, such as tr0, run the command:
# ifconfig tr0 up
To activate a network interface, such as the loopback interface (lo0) and assign it
an IP address, run the command:
# ifconfig lo0 127.0.0.1 up
To activate a network interface, such as a token ring interface (tr0), and assign it
an IP address and netmask, run the command:
# ifconfig tr0 10.1.2.3 netmask 255.255.255.0 up
290 IBM ^ Certification Study Guide - pSeries AIX System Administration
10.12.3 Deactivating a network interface
To stop messages from being transmitted through an interface, the interface must
be placed in the down or inactive state. To deactivate an interface using
ifconfig, run the command:
# ifconfig Interface down
For example, to deactivate the network interface tr0, run the command:
# ifconfig tr0 down
10.12.4 Deleting an address from a network interface
To remove a network address from an interface, the address must be deleted
from the interface definition. To delete a network address from an interface using
ifconfig, run the command:
# ifconfig Interface [Address] [netmask Netmask] delete
For example, to delete the network address from tr0, run the command:
# ifconfig tr0 delete
10.12.5 Detaching a network interface
To remove an interface from the network interface list, the interface must be
detached from the system. This command can be used when a network interface
card has physically been removed from a system or when an interface no longer
needs to be defined within the system. To detach a network interface from the
system using ifconfig, run the command:
# ifconfig Interface detach
For example, to remove the interface tr0 from the network interface list, run the
command:
# ifconfig tr0 detach
Note: This command does not remove any IP addresses assigned to the
interface from the system, nor does it remove the interface from the network
interface list.
Note: This command does not place the interface in the down state, nor does
it remove the interface from the network interface list.
Chapter 10. Network administration 291
10.12.6 Creating an IP alias for a network interface
Through the ifconfig command, you can bind multiple network addresses to a
single network interface by defining an alias. This is a useful tool for such
activities as providing two different initial home pages through a Web server
application. To bind an alias to a network interface, run the command:
# ifconfig Interface Address [netmask Netmask] alias
For example, to bind the IP address of 10.1.2.3 to tr0 with a netmask of
255.255.255.0, run the command:
# ifconfig tr0 10.1.2.3 netmask 255.255.255.0 alias
When this alias is no longer required, you can remove it using the command:
ifconfig tr0 10.1.2.3 netmask 255.255.255.0 delete
Note: This command removes all network addresses assigned to the interface
and removes the interface from the output of the ifconfig -a command. To
add an interface back to the system, or to add a new interface to the network
interface list, run the command:
# ifconfig Interface
where Interface is the network interface you want to add.
Note: There will be no ODM record created of the alias by this command. You
will need to invoke the same command every time you reboot your system to
preserve the alias. If your system configuration has a local startup script
defined in the /etc/inittab file, this command should be included in that local
startup script.
Note: If you do not specify which alias is to be removed from a network
interface, the system will default and remove the primary network address
from the interface. After this occurs, the first alias in the list of network
addresses for the interface will become the primary network address for the
interface. To remove all aliases from an interface, you must delete each alias
individually.
292 IBM ^ Certification Study Guide - pSeries AIX System Administration
10.12.7 Changing the MTU size of a network interface
When messages are transmitted through a network interface, they travel in
bundles of information called packets. These packets can vary in length from 60
bytes to 65535 bytes per packet. By default, a 16 Mb token-ring interface will
transmit packets that are 1492 bytes long, and Ethernet interfaces will transmit
packets that are 1500 bytes long. For AIX systems, these packets are governed
by the maximum transmission unit (MTU) size variable.
The MTU size is critical for proper network communications. Packets that are too
small in length may be lost during transmission. Packets that are too long in
length may collide with other packets that are being transmitted. These factors
can lead to slower transmission rates and other network problems as packets
must then be retransmitted.
To determine the MTU size for a network interface, run the command:
# lsattr -El Interface
The output will look similar to the following:
# lsattr -El tr1
mtu 1492 Maximum IP Packet Size for This Device True
mtu_4 1492 Maximum IP Packet Size for 4 Mbit ring speed True
mtu_16 1492 Maximum IP Packet Size for 16 Mbit ring speed True
mtu_100 1492 Maximum IP Packet Size for 100 Mbit ring speed True
...
The ifconfig command can adjust the MTU size for a network interface. To
change the MTU size, run the command:
# ifconfig Interface mtu Value
For example, to change the MTU size of tr1 to 12000 bytes in length, run the
command:
# ifconfig tr1 mtu 12000
Note: The minimum and maximum MTU sizes for specific interfaces may vary.
See “Automatic Configuration of Network Interfaces” in the AIX 5L Version 5.1
System Management Guide: Communications and Networks as part of the
AIX product documentation for more information.
Note: The MTU size cannot be changed while the interface is in use. All
systems that are on the same local area network (LAN) must have the same
MTU size, so all systems must change MTU size simultaneously to prevent
problems.
Chapter 10. Network administration 293
10.13 Network security
Network security is a prevalent issue for system administrators. There is a great
need for secure connections, trusted networks, and other ways of
communications that do not allow for unauthorized system access. This section
briefly describes some of the more common ways you can prevent unauthorized
access to your systems over your networks.
10.13.1 Trusted and non-trusted processes
A trusted program, or trusted process, is a shell script, a daemon, or a program
that meets a particular standard of security. These security standards are set and
maintained by the U.S. Department of Defense, which also certifies some trusted
programs.
TCP/IP contains several trusted daemons and many non-trusted daemons. The
trusted daemons have been tested to ensure that they operate within particular
security standards, such as granting users a particular level of access and only
permitting users to perform certain tasks.
Examples of trusted daemons are:
ftpd
rexecd
telnetd
The trusted types of daemons require verification and authentication of the user
wishing to communicate with the server. Typically, this is done through the use of
a login and password.
Examples of non-trusted daemons are:
rshd
rlogind
tftpd
The non-trusted types of daemons do not always require verification or
authentication of the user wishing to communicate with the server. A login and
password is not necessarily required for the use of these types of daemons.
Caution should be used in enabling these processes to run on your system.
294 IBM ^ Certification Study Guide - pSeries AIX System Administration
10.13.2 The $HOME/.netrc file
The $HOME/.netrc file contains information used by the automatic login feature
of the rexec and ftp commands. It is a hidden file in a user's home directory and
must be owned either by the user executing the command or by the root user. If
the .netrc file contains a login password, the file's permissions must be set to 600
(read and write by owner only). The login password is in plain text. Even with
permissions set to 600, passwords for remote systems are vulnerable to being
revealed to any user with root authority.
Entries in the $HOME/.netrc file are stored in the following format (separated by
spaces, tabs, or new lines):
machine HostName The HostName variable is the name of a remote host.
This entry begins the definition of the automatic login
process for the specified host. All following entries up to
the next machine entry or the end of the file apply to that
host.
login UserName The UserName variable is the full domain user name for
use at the remote host. If this entry is found, the automatic
login process initiates a login using the specified name. If
this entry is missing, the automatic login process is
unsuccessful.
password Password The Password variable is the login password to be used.
The automatic login process supplies this password to the
remote server. A login password must be established at
the remote host, and that password must be entered in
the .netrc file. Otherwise, the automatic login process is
unsuccessful, and the user is prompted for the login
password.
account Password The Password variable is the account password to be
used. If this entry is found, and an account password is
required at the remote host, the automatic login process
supplies the password to the remote server. If the remote
host requires an account password, but this entry is
missing, the automatic login process prompts for the
account password.
macdef MacroName The MacroName variable is the name of an FTP
subcommand macro. The macro is defined to contain all
of the following FTP subcommands up to the next blank
line or the end of the file. If the macro is named init, the
ftp command executes the macro upon successful
completion of the automatic login process. The rexec
command does not recognize a macdef entry.
Chapter 10. Network administration 295
A sample $HOME/.netrc file is shown Figure 10-19.
Figure 10-19 A sample .netrc file
10.13.3 The /etc/hosts.equiv and $HOME/.rhosts files
The /etc/hosts.equiv file, along with any local $HOME/.rhosts files, defines the
hosts (computers on a network) and user accounts that can invoke remote
commands on a local host without supplying a password. A user or host that is
not required to supply a password is considered trusted, though the daemons
that initiate the connections may be nontrusted in nature (for example, rlogind).
When a local host receives a remote command request, the appropriate local
daemon first checks the /etc/hosts.equiv file to determine if the request originates
with a trusted user or host. For example, if the local host receives a remote login
request, the rlogind daemon checks for the existence of a hosts.equiv file on the
local host. If the file exists, but does not define the host or user, the system
checks the appropriate $HOME/.rhosts file. This file is similar to the
/etc/hosts.equiv file, except that it is maintained for individual users.
Both files, /etc/hosts.equiv and $HOME/.rhosts, must have permissions denying
write access to group and other (600). If either group or other have write access
to a file, that file will be ignored. Do not give write permission to the
/etc/hosts.equiv file to group and others, as this can lead to security
vulnerabilities and undesired user access to the local host.
Note: The maximum size of the .netrc file is 4096 bytes. If you need to use
more than 4096 bytes, you have to split up your file into multiple parts and
write a script to automate functions like FTP jobs.
Note: If a remote command request is made by the root user, the
/etc/hosts.equiv file is ignored and only the /.rhosts file is read.
296 IBM ^ Certification Study Guide - pSeries AIX System Administration
The format of the /etc/hosts.equiv and $HOME/.rhosts files is as follows:
[ + | - ] HostName [ + | - ] UserName or @NetGroup
For example, to allow all the users on the hosts toaster and machine to log in to
the local host, you would enter:
toaster
machine
To only allow the user bob to log in from the host machine, you would enter:
toaster
machine bob
To allow the user lester to log in from any host, you would enter:
toaster
machine bob
+ lester
To allow all users from the host tron to log in, while requesting users joel and
mike for a password to log in, you would enter:
toaster
machine bob
+ lester
tron -joel
tron -mike
tron
To deny all members of the forum netgroup from logging in automatically, you
would enter:
toaster
machine bob
+ lester
tron -joel
tron -mike
tron
- @forum
Note: Both /etc/hosts.equiv and $HOME/.rhosts are read top to bottom, so the
order of placing entries into these files can change the desired results. The
deny, or - (minus sign), statements must precede the accept, or + (plus sign),
statements in the lists.
Chapter 10. Network administration 297
10.13.4 The securetcpip command
The securetcpip command provides enhanced security for the network on a
host. It performs the following tasks:
Disables the nontrusted commands and daemons: rcp, rlogin, rlogind, rsh,
rshd, tftp, and tftpd. The disabled commands and daemons are not deleted;
instead, they are changed to mode 0000. You can enable a particular
command or daemon by re-establishing a valid mode. The /.netrc file is not
used by any programs when the securetcpip command has been run on your
system.
Adds a TCP/IP security stanza to the /etc/security/config file. The stanza is in
the following format:
tcpip:
netrc = ftp,rexec /* functions disabling netrc */
After issuing the securetcpip command, shut down and restart your system. All
of your TCP/IP commands and network interfaces should be properly configured
after the system restarts.
10.13.5 Anonymous FTP
Anonymous FTP is a feature that allows users to transfer files in some file
directories on your system through ftp without having a unique login for each
user. This is a useful tool in areas such as releasing patches for software, when
large quantities of users worldwide may need access to a specific system. The
user only needs to use the login name anonymous and password of guest or
some other common password convention (typically the user’s Internet e-mail ID)
Note: Netgroups is a feature of NIS and of AIX 5L Version 5.1 that allows an
administrator to easily classify hosts and users into common groups. The use
of netgroups is outside the scope of this book. More information on netgroups
can be found in the AIX 5L Version 5.1 System Management Guide:
Communications and Networks that is part of the AIX product documentation.
Note: Before running the securetcpip command, quiesce the system by
logging in as root and executing the killall command to stop all network
daemons. The killall command kills all processes except the calling
process. If users are logged in or applications are running, have them exit or
finish before executing the killall command.
298 IBM ^ Certification Study Guide - pSeries AIX System Administration
To setup anonymous FTP on a server running AIX 5L Version 5.1, run the script:
# /usr/samples/tcpip/anon.ftp
This will create the appropriate users and directories for using anonymous FTP.
10.13.6 FTP logging
By default, FTP does not log connections or file transfers from users accessing
the system. This can be a security risk when users use anonymous FTP to
transfer files to or from your system. To enable FTP logging, do the following:
1. Edit the /etc/syslog.conf file and add the line:
daemon.info FileName
where FileName is the name of the log file that will track FTP activity, both by the
anonymous and other user IDs. FileName must exist before you perform the next
step of this process.
2. Run the command refresh -s syslogd to refresh the syslogd daemon.
3. Edit the /etc/inetd.conf file, and modify the line containing ftpd as follows:
ftp stream tcp6 nowait root /usr/sbin/ftpd ftpd -l
4. Run the command refresh -s inetd to refresh the inetd daemon.
When users use the ftp command to access your system, their login and file
transfer activity will be logged in FileName. This log will look similar to the
following:
Sep 5 13:56:47 localhost ftpd[17958]: connection from server2.example.ibm.com
at Wed Sep 5 13:56:47 2001
Sep 5 13:56:52 localhost ftpd[17958]: ANONYMOUS FTP LOGIN FROM
server2.example.ibm.com, sampleid@server1.example.ibm.com
Sep 5 13:57:17 localhost ftpd[17958]: FTPD: IMPORT file local testfile, remote
In this sample, a user established an anonymous FTP connection from
server1.example.ibm.com. As a password, the user provided the e-mail address
of sampleid@server1.example.ibm.com. The user used the FTP command put
to upload the file testfile to server2.
FTP logging does not record when a user quits an FTP session. To determine if
someone is still logged onto your system, run a ps -fp on the PID provided
within the brackets ([17958]).
FTP log files will grow in proportion to how many users access your system and
how many file transfers take place. We recommend that you monitor the growth
of your FTP log to prevent potential system problems.
Chapter 10. Network administration 299
10.14 The uname command
Apart from the hostname command, you can also use the uname -n command to
display the host name of your system. Without any flags, the uname command will
display the operating system that your are using.
You can also use the uname -x command to display:
The operating system that your are using
The host name
The machine ID number of the hardware running the system
The release number of the operating system
The operating system version
The system model name
A few examples of the use of the uname command are shown in Figure 10-20.
Figure 10-20 The uname command
10.15 Basic network problem determination
When a user informs you that a certain system cannot be accessed, check for
various network problems. Typically, you will go through these TCP/IP problem
determination topics using whichever is applicable to your environment:
Communication problems
Name resolution problems
Routing problems
Problems with System Resource Controller (SRC) support
Telnet or rlogin problems
Configuration problems
Common problems with network interfaces
Problems with packet delivery
300 IBM ^ Certification Study Guide - pSeries AIX System Administration
Problems with Dynamic Host Configuration Protocol (DHCP)
However, there are other considerations outside the network area that you
should check also:
The server system may be down.
This will usually reveal itself when you check for communication problems.
The ping command will lead you to the problem system. The whole system
may be down or the network interface may be down.
The paging space may be full.
If a user has logged in, this will be fairly obvious as there is usually a system
message stating not enough paging space or not enough memory. However,
if a user is trying to telnet or ftp to the system, there will be time outs as the
system cannot create additional processes, or the system may be busy killing
processes.
A file system may be full.
If the user can access the system, but there are problems with certain
functions, you should check all areas in the system. If the user cannot start
the Web Based System Manager (WSM), the /tmp filesystem may be full.
A file system may not have been mounted.
Usually, the user will mention losing all his files.
Not all problems are caused by the network and the network function. Make sure
you understand your user’s problem before concluding that it is a network
problem.
10.16 Quiz
The following are additional questions created by the authors to further test your
understanding of the topics.
1. Which of the following actions allow a System Administrator to configure
anonymous FTP?
A. smit ftp
B. /usr/samples/tcpip/anon.ftp
C. startsrc -s ftp -a anonymous
D. add the FTP anonymous user using smit
Chapter 10. Network administration 301
2. A System Administrator is given only one Ethernet network card (en0) in a
system, with an IP address of 192.168.1.3. A user wants to host two different
initial home pages on the Web server. The System Administrator has verified
that the Web server does support multiple IP Addresses. To add another IP
address to the already configured interface, which of the following choices
should be selected?
A. smitty chgenet
B. smitty add_interface
C. ifconfig en0 newipaddress netmask netmask alias
D. This task cannot be accomplished without adding a new Ethernet
interface.
3. When a RPC (remote procedural call) server starts up, it registers itself with
which of the following daemons?
A. yp daemons
B. nfs daemons
C. inetd daemons
D. portmap daemon
The following are additional questions created by the authors to further test your
understanding of the topics.
1. Which of the following actions will allow the system administrator to stop and
restart the TCP/IP daemons manually?
A. Use the netstat command.
B. Use the SRC utility to stop and restart.
C. Use the netconfig utility menu.
D. Issue the rmdev command on the appropriate network adapter.
2. Two Web servers need to be configured on a single machine that has only
one network interface. Each Web server needs to have its own unique IP
address. How should an administrator accomplish this?
A. Use the smitty alias command
B. Add it in /etc/defaults
C. Use the newaliases 192.127.10.10 command
D Use the ifconfig en0 192.127.10.10 alias command
302 IBM ^ Certification Study Guide - pSeries AIX System Administration
10.16.1 Answers
The following answers are for the assessment quiz questions.
1. B
2. C
3. D
The following answers are for the additional quiz questions.
1. B
2. D
10.17 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. After installing a new network adapter or after replacing a Token Ring adapter
with an Ethernet adapter, what are the steps to restart TCP/IP?
2. Configure a network interface using SMIT.
3. Start and stop TCP/IP daemons using /etc/rc.tcpip and /etc/tcp.clean.
4. Name the SMIT fast paths needed for networking, such as tcpip, route, and
others.
5. Change the IP address using SMIT.
6. Describe the inetd, portmap, and other TCP/IP daemons. What errors will
users experience when any one of the TCP/IP daemons is not started?
7. What are the errors if the /etc/resolv file is incorrect?
8. How do you add a route?
9. Create and delete an IP alias using the ifconfig command.
10.Does ping work without starting TCP/IP?
11.Use the $HOME/.netrc file to eliminate the user login and password prompts
for the rexec and ftp commands.
© Copyright IBM Corp. 2001 303
Chapter 11. Network File System
administration
The Network File System (NFS) is a distributed file system that allows users to
access files and directories of remote servers as if they were local. For example,
the user can use operating systems commands to create, remove, read, write,
and set file attributes for remote files and directories. NFS is independent of
machine types, operating systems, and network architectures through the use of
remote procedure calls (RPC). This section discusses the tasks that can be
performed by an administrator in an NFS environment.
11
304 IBM ^ Certification Study Guide - pSeries AIX System Administration
11.1 NFS services
NFS provides its services through a client-server relationship. The computers
that make their file systems, directories, and other resources available for remote
access are called
servers. The act of making file systems available is called
exporting. The computers, or the processes they run, that use a server's
resources are considered
clients. Once a client mounts a file system that a
server exports, the client can access the individual server files. Access to
exported directories can be restricted to specific clients.
The following are a list of terms that are used throughout this discussion:
Server A computer that makes its file systems, directories, and
other resources available for remote access.
Clients The computers, or their processes, that use a server’s
resources.
Export The act of making file systems available to remote clients.
Mount The act of a client accessing the file systems that a server
exports.
The major services provided by NFS are:
Mount From the /usr/sbin/rpc.mountd daemon on the server and
the /usr/sbin/mount command on the client. The mountd
daemon is a Remote Procedure Call (RPC) that answers
a client request to mount a file system. The mountd
daemon finds out which file systems are available by
reading the /etc/xtab file. In addition, the mountd daemon
provides a list of currently mounted file systems and the
clients on which they are mounted.
Remote file access From the /usr/sbin/nfsd daemon on the server and the
/usr/sbin/biod daemon on the client. Handles client
requests for files. The biod daemon runs on all NFS client
systems. When a user on a client wants to read or write to
a file on a server, the biod daemon sends this request to
the server.
Boot parameters Provides boot parameters to SunOS diskless clients from
the /usr/sbin/rpc.bootparamd daemon on the server.
PC authentication Provides a user authentication service for PC-NFS from
the /usr/sbin/rpc.pcnfsd daemon on the server.
Chapter 11. Network File System administration 305
An NFS server is
stateless. That is, an NFS server does not have to remember
any transaction information about its clients. In other words, NFS transactions
are atomic: A single NFS transaction corresponds to a single, complete file
operation. NFS requires the client to remember any information needed for later
NFS use.
Figure 11-1 is an illustration of the NFS configuration discussed in this section.
Figure 11-1 A typical NFS environment
The environment illustrated in Figure 11-1 includes two NFS servers and three
clients where one system is both a server and a client. The CRoom server
exports its directories allowing all other systems to have access to them. The
Accounts server shares one directory that only Marketing has access to. The
following section references the scenario illustrated and discusses any
challenges and tasks that arise while administrating NFS in this environment.
11.2 Planning, installation, and configuration of NFS
There are no specific installation tasks needed for NFS, as the Base Operating
System (BOS) Installation also includes the default installation of network
services, such as TCP/IP and NFS.
CRoom
HResources
Marketing
Accounts
/home1
/home2
/home3
/home4
/home1
/home2
/home3
/home4
/home1
/home2
/home3
/home4
/home1
/home2
/home3
/home4
/backup
Exported
Exported
/backup
Mounted
Mounted
Mounted
NFS Server
NFS Server and Client
NFS Client
306 IBM ^ Certification Study Guide - pSeries AIX System Administration
Before starting the configuration of NFS on any of the systems, perform the
following tasks:
1. Identify which systems in the network will be servers and which will be clients.
As shown in Figure 11-1, CRoom and Accounts are servers, and
HResources, Accounts, and Marketing are clients. Note that Accounts is both
a client and server.
2. Start the NFS daemons for each system (whether client or server). The NFS
daemons, by default, are not started on a newly installed system. When a
system is first installed, all of the files are placed on the system, but the steps
to activate NFS are not taken. The daemons can be started by:
– Using the SMIT fast path smitty mknfs
– Using the mknfs command to start the NFS daemons immediately, and this
should produce the following:
# mknfs -N
0513-059 The portmap Subsystem has been started. Subsystem PID is 23734.
Starting NFS services:
0513-059 The biod Subsystem has been started. Subsystem PID is 27264.
0513-059 The nfsd Subsystem has been started. Subsystem PID is 30570.
0513-059 The rpc.mountd Subsystem has been started. Subsystem PID is 28350.
0513-059 The rpc.statd Subsystem has been started. Subsystem PID is 15298.
0513-059 The rpc.lockd Subsystem has been started. Subsystem PID is 30976.
#
Table 11-1 lists the most common flags of the mknfs command.
Table 11-1 Flags for the mknfs command
The -B and -l options place an entry in the inittab file so that the /etc/rc.nfs script
is run each time the system restarts. This script, in turn, starts all NFS daemons
required for a particular system.
Use the following instructions to configure CRoom and Accounts as an NFS
server:
1. Start the NFS daemons using SRC if not already started.
Flag Description
-B Adds an entry to the inittab file to execute the /etc/rc.nfs file on
system restart. The mknfs command also executes the /etc/rc.nfs
file immediately to start the NFS daemons. This flag is the default.
-I Adds an entry to the inittab file to execute the /etc/rc.nfs file on system
restart.
-N Starts the /etc/rc.nfs file to start the NFS daemons immediately. When
started this way, the daemons run until the next system restart.
Chapter 11. Network File System administration 307
The NFS daemons can be started individually or all at once. Use the following
command to start NFS daemons individually:
startsrc -s daemon
where daemon is any one of the SRC controlled daemons (See Section 11.4,
“NFS files, commands, and daemons reference” on page 321). For example,
to start the nfsd daemon:
startsrc -s nfsd
Use the following command to start all of the NFS daemons:
startsrc -g nfs
2. Create the exports in the /etc/exports file.
11.2.1 Exporting NFS directories
This section discusses the use of the exportfs command.
Exporting an NFS directory using SMIT
To export file systems using SMIT, follow this procedure:
1. Verify that NFS is already running on CRoom and Accounts servers using the
command lssrc -g nfs. As in the following example, the output should
indicate that the nfsd and the rpc.mountd daemons are active. If they are not,
start NFS using the instructions in Section 11.2, “Planning, installation, and
configuration of NFS” on page 305.
# lssrc -g nfs
Subsystem Group PID Status
biod nfs 15740 active
nfsd nfs 11376 active
rpc.mountd nfs 5614 active
rpc.statd nfs 16772 active
rpc.lockd nfs 15496 active
#
Note: If the /etc/exports file does not exist, the nfsd and the rpc.mountd
daemons will not be started. You can create an empty /etc/exports file
by running the command touch /etc/exports. This will allow the nfsd
and the rpc.mountd daemons to start, although no file systems will be
exported.
308 IBM ^ Certification Study Guide - pSeries AIX System Administration
2. Use smitty mknfsexp to export the directory; the SMIT screen is as shown in
Figure 11-2.
Figure 11-2 Adding a directory to the export list
3. For CRoom Server, specify /home1, and on Accounts /backup in the
PATHNAME of directory to export field, set the MODE to export directory field
to read-write, and set the EXPORT directory now, system restart, or both field
to both.
4. Specify any other optional characteristics you want, or accept the default
values by leaving the remaining fields as they are. For this illustration, for
Accounts, set the Hosts and NetGroups allowed client access field to
Marketing and keep the default for everything else.
5. When you have finished making your changes, SMIT updates the /etc/exports
file. If the /etc/exports file does not exist, it will be created.
6. Repeat steps 3 through 5 for directories /home2, /home3, /home4 on CRoom.
Accounts is only exporting /backup; there is no need to do any other exports.
7. If NFS is currently running on the servers, enter:
/usr/sbin/exportfs -a
The -a option tells the exportfs command to send all information in the
/etc/exports file to the kernel. If NFS is not running, start NFS using the
instructions in Section 11.2, “Planning, installation, and configuration of NFS”
on page 305.
Chapter 11. Network File System administration 309
8. Verify that all file systems have been exported properly as follows:
For the CRoom Server:
# showmount -e CRoom
export list for CRoom:
/home1 (everyone)
/home2 (everyone)
/home3 (everyone)
/home4 (everyone)
#
For the Accounts Server:
# showmount -e Accounts
export list for Accounts:
/backup Marketing
#
Exporting an NFS directory using a text editor
To export file systems using a text editor, follow this procedure:
1. Open the /etc/exports file with your favorite text editor.
vi /etc/exports
2. Create an entry for each directory to be exported by using the full path name
of the directory as shown in Figure 11-3.
.
Figure 11-3 Content of /etc/exports for CRoom server
310 IBM ^ Certification Study Guide - pSeries AIX System Administration
3. List each directory to be exported starting in the left margin. No directory
should include any other directory that is already exported. Save and close
the /etc/exports file.
4. If NFS is currently running on the servers, enter:
/usr/sbin/exportfs -a
Exporting an NFS directory temporarily
A file system can be exported when needed, and as such, does not change the
/etc/exports file. This is done by entering:
exportfs -i /dirname
where /dirname is the name of the file system you want to export. The exportfs
-i command specifies that the /etc/exports file is not to be checked for the
specified directory, and all options are taken directly from the command line.
For each system that is to be a client (HResources, Accounts, and Marketing),
the following steps will ensure that they have access to directories and files on
the CRoom and Accounts Servers.
1. Verify that NFS is the default remote file system. If this is not done, you will
need to specify the -v nfs flag when using the mount command. Using a text
editor, open the /etc/vfs file and search for the following entries:
%defaultvfs jfs nfs
nfs 2 /sbin/helpers/nfsmnthelp none remote
If pound signs (#) appear at the beginning of the previous lines, delete the
pound signs.
2. Save and close the /etc/vfs file.
3. Start NFS using the instructions in Section 11.2, “Planning, installation, and
configuration of NFS” on page 305.
4. Go to Section 11.2.3, “Mounting an NFS directory” on page 311.
11.2.2 Unexporting an NFS directory
You can unexport an NFS directory by using one of the following procedures:
To unexport an NFS directory using SMIT:
a. On the CRoom Server, enter the following command to remove /home4
export:
smitty rmnfsexp
b. Enter /home4 in the PATHNAME of exported directory to be removed field.
The directory is now removed from the /etc/exports file and is unexported.
Chapter 11. Network File System administration 311
To unexport an NFS directory using a text editor:
a. Open the /etc/exports file with a text editor.
b. Find the entry for the directory you wish to unexport, that is, /home4, and
then delete that line.
c. Save and close the /etc/exports file.
d. If NFS is currently running, enter:
exportfs -u dirname
where dirname is the full path name of the directory (/home4) you just
deleted from the /etc/exports file.
11.2.3 Mounting an NFS directory
There are three types of NFS mounts: Predefined, explicit, and automatic.
Predefined mounts are specified in the /etc/filesystems file. Each stanza (or
entry) in this file defines the characteristics of a mount, as shown in Figure 11-4.
Figure 11-4 Example NFS stanza in the /etc/filesystems file
Data, such as the host name, remote path, local path, and any mount options,
are listed in this stanza. Predefined mounts should be used when certain mounts
are always required for proper operation of a client.
Explicit mounts serve the needs of the root user. Explicit mounts are usually
done for short periods of time when there is a requirement for occasional
unplanned mounts. Explicit mounts can also be used if a mount is required for
special tasks, and that mount should not be generally available on the NFS client.
These mounts are usually fully qualified on the command line by using the mount
command with all needed information.
Explicit mounts do not require updating the /etc/filesystems file. File systems
mounted explicitly remain mounted unless explicitly unmounted with the umount
command or until the system is restarted.
/home1:
dev = "/home1"
vfs = nfs
nodename = CRoom
mount = true
options = bg,hard,intr
account = false
312 IBM ^ Certification Study Guide - pSeries AIX System Administration
Automatic mounts are controlled by the automount command, which causes the
AutoFS kernel extension to monitor specified directories for activity. If a program
or user attempts to access a directory that is not currently mounted, then AutoFS
intercepts the request, arranges for the mount of the file system, and then
services the request.
NFS mounting process
Clients access files on the server by first mounting a server's exported
directories. When a client mounts a directory, it does not make a copy of that
directory. Rather, the mounting process uses a series of remote procedure calls
to enable a client to access the directories on the server transparently. The
following describes the mounting process:
1. When the server starts, the /etc/rc.nfs script runs the exportfs command,
which reads the server /etc/exports file and then tells the kernel which
directories are to be exported and which access restrictions they require.
2. The rpc.mountd daemon and several nfsd daemons (eight, by default) are
then started by the /etc/rc.nfs script.
3. When the client starts, the /etc/rc.nfs script starts several biod daemons
(eight, by default), which forward client mount requests to the appropriate
server.
4. Then the /etc/rc.nfs script executes the mount command, which reads the file
systems listed in the /etc/filesystems file.
5. The mount command locates one or more servers that export the information
the client wants and sets up communication between itself and that server.
This process is called
binding.
6. The mount command then requests that one or more servers allow the client
to access the directories in the client /etc/filesystems file.
7. The server rpc.mountd daemon receives the client mount requests and either
grants or denies them. If the requested directory is available to that client, the
rpc.mountd daemon sends the client's kernel an identifier called a
file handle.
8. The client kernel then ties the file handle to the mount point (a directory) by
recording certain information in a mount record.
Once the file system is mounted, the client can perform file operations. When the
client does a file operation the biod daemon sends the file handle to the server,
where the file is read by one of the nfsd daemons to process the file request.
Assuming the client has access to perform the requested file operation, the nfsd
daemon returns the necessary information to the client's biod daemon.
Chapter 11. Network File System administration 313
The following procedure helps to complete the scenario shown in Figure 11-1 on
page 305.
1. On HResources, establish the local mount point for /home1 on server CRoom
using the mkdir command.
mkdir /home1
This directory should be empty. This mount point can be created like any
other directory, and no special attributes are needed for this directory.
2. On HResources, establish and mount the predefined mounts by following the
instructions in “Establishing predefined NFS mounts” on page 313.
Establishing predefined NFS mounts
You can establish predefined NFS mounts using one of the following procedures.
To establish predefined mounts through SMIT (Figure 11-5 on page 314), use
the following command:
smitty mknfsmnt
Note: The mount points for all NFS mounts must exist on your system
before you can mount a file system with one exception. If the automount
daemon is used, it may not be necessary to create mount points. See
“Mounting an NFS directory automatically” on page 317.
Note: Define the bg (background) and intr (interruptible) options in the
/etc/filesystems file when establishing a predefined mount that is to be
mounted during system startup. Mounts that are non-interruptible and
running in the foreground can hang the client if the network or server is
down when the client system starts up. If a client cannot access the
network or server, the user must start the machine again in maintenance
mode and edit the appropriate mount requests.
314 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 11-5 Add a File System for Mounting screen
Specify values in this screen for each mount you want predefined. You must
specify a value for each required field (those marked with an asterisk (*) in the
left margin). You may specify values for the other fields or accept their default
values. This method creates an entry in the /etc/filesystems file for the desired
mount and attempts the mount.
To establish the NFS default mounts by editing the /etc/filesystems file (only use
this method under special circumstances), perform the following:
1. Open the /etc/filesystems file on HResources with a text editor. Add entries for
each of the remote file systems that you want mounted when the system is
started. For example:
/home1:
dev = /home1
mount = false
vfs = nfs
nodename = CRoom
options = ro,soft
type = nfs_mount
Chapter 11. Network File System administration 315
This stanza directs the system to mount the /home1 remote directory over the
local mount point of the same name. The file system is mounted as read-only
(ro). Because it is also mounted as soft, an error is returned in the event the
server does not respond. By specifying the type parameter as nfs_mount, the
system attempts to mount the /home1 file system (along with any other file
systems that are specified in the type = nfs_mount group) when the mount -t
nfs_mount command is issued.
The following example stanza directs the system to mount the /home2 file
system at system startup time. If the mount fails, the bg option tells the
system to continue attempting the mount in the background.
/home2:
dev = /home2
mount = true
vfs = nfs
nodename = CRoom
options = ro,soft,bg
type = nfs_mount
2. Remove any directory entries that you do not want to mount automatically at
system startup.
3. Save and close the file.
4. Run the mount -a command to mount all the directories specified in the
/etc/filesystems file.
5. On Marketing, repeat mount for /backup directory from Accounts
The NFS directory is now ready to use.
Mounting an NFS directory explicitly
To mount an NFS directory explicitly, use the following procedure:
1. Verify that the NFS server has exported the directory, using:
showmount -e ServerName
For Server CRoom:
# showmount -e CRoom
export list for CRoom:
/home1 (everyone)
/home2 (everyone)
/home3 (everyone)
/home4 (everyone)
#
Note: See “Parameters” on page 318 for additional parameters.
316 IBM ^ Certification Study Guide - pSeries AIX System Administration
where ServerName is the name of the NFS server. This command displays
the names of the directories currently exported from the NFS server. If the
directory you want to mount is not listed, export the directory from the server.
2. Establish the local mount point using the mkdir command. For NFS to
complete a mount successfully, a directory that acts as the mount point of an
NFS mount must be present. This directory should be empty. This mount
point can be created like any other directory, and no special attributes are
needed for this directory.
3. On the HResources machine, enter the following SMIT fast path:
smitty mknfsmnt
4. Make changes to the following fields that are appropriate for your network
configuration. Your configuration may not require completing all of the entries
on this screen.
– PATHNAME of mount point.
– PATHNAME of remote directory.
– HOST where remote directory resides.
– MOUNT now, add entry to /etc/filesystems
– /etc/filesystems entry will mount the directory on system RESTART.
– MODE for this NFS.
5. Use the default values for the remaining entries or change them depending on
your NFS configuration.
6. When you finish making all the changes on this screen, SMIT mounts the
NFS.
7. When the Command: field shows the OK status, exit SMIT.
The NFS is now ready to use.
Note: If you are using the ASCII SMIT interface, press the Tab key to
change to the correct value for each field, but do not press Enter until
you get to step 7.
Chapter 11. Network File System administration 317
Mounting an NFS directory automatically
AutoFS relies on the use of the automount command to propagate the automatic
mount configuration information to the AutoFS kernel extension and start the
automountd daemon. Through this configuration propagation, the extension
automatically and transparently mounts file systems whenever a file or a
directory within that file system is opened. The extension informs the automountd
daemon of mount and unmount requests, and the automountd daemon actually
performs the requested service.
Because the name-to-location binding is dynamic within the automountd
daemon, updates to a Network Information Service (NIS) map used by the
automountd daemon are transparent to the user. Also, there is no need to
pre-mount shared file systems for applications that have hard-coded references
to files and directories, nor is there a need to maintain records of which hosts
must be mounted for particular applications.
AutoFS allows file systems to be mounted as needed. With this method of
mounting directories, all file systems do not need to be mounted all of the time,
only those being used are mounted.
For example, to mount the /backup NFS directory automatically:
1. Verify that the NFS server has exported the directory by entering:
# showmount -e Accounts
export list for Accounts:
/backup Marketing
#
This command displays the names of the directories currently exported from
the NFS server.
2. Create an AutoFS map file. AutoFS will mount and unmount the directories
specified in this map file. For example, suppose you want to use AutoFS to
mount the /backup directory as needed from the Accounts server onto the
remote /backup directory. In this example, the map file name is
/tmp/mount.map. An example of a map file can be found in /usr/samples/nfs.
3. Ensure that the AutoFS kernel extension is loaded and the automountd
daemon is running. This can be accomplished in two ways:
a. Using SRC, enter:
lssrc -s automountd
If the automountd subsystem is not running, issue: startsrc -s
automountd
318 IBM ^ Certification Study Guide - pSeries AIX System Administration
b. Using the automount command, issue /usr/sbin/automount -v. Define the
map file using the command line interface by entering:
/usr/sbin/automount -v /backup /tmp/mount.map
where /backup is the AutoFS mount point on the client. Now, if a user runs
the cd /backup command, the AutoFS kernel extension will intercept
access to the directory and will issue a remote procedure call to the
automountd daemon, which will mount the /backup directory and then
allow the cd command to complete.
4. To stop the automountd, issue the stopsrc -s automountd command.
If, for some reason, the automountd daemon was started without the use of
SRC, issue:
kill automountd_PID
where automountd_PID is the process ID of the automountd daemon.
(Running the ps -e command will display the process ID of the automountd
daemon.) The kill command sends a SIGTERM signal to the automountd
daemon.
Parameters
The parameters required for stanzas pertaining to NFS mounts are:
dev=file_system_name Specifies the path name of the remote file system
being mounted.
mount=[true|false] If true, specifies that the NFS will be mounted when
the system boots. If false, the NFS will not be mounted
when the system boots.
nodename=hostname Specifies the host machine on which the remote file
system resides.
vfs=nfs Specifies that the virtual file system being mounted is
an NFS.
If you do not set the following options, the kernel automatically sets them to the
following default values:
biods=6
fg
retry=10000
rsize=8192
wsize=8192
timeo=7
retrans=3
Chapter 11. Network File System administration 319
port=NFS_PORT
hard
secure=off
acregmin=3
acregmax=60
acdirmin=30
acdirmax=60
11.3 Administration of NFS servers and clients
In this section, we will discuss the operations performed by a system
administrator working with NFS. The topics being discussed are:
The status of the NFS daemons
Changing exported NFSs
Using the unmount command
11.3.1 Getting the Current Status of the NFS Daemons
You can get the current status of the NFS daemons individually or all at once. To
get the current status of the NFS daemons individually, enter:
lssrc -s daemon
where daemon is any one of the SRC controlled daemons. For example, to get
the current status of the rpc.lockd daemon, enter:
lssrc -s rpc.lockd
To get the current status of all NFS daemons at once, enter:
lssrc -g nfs
320 IBM ^ Certification Study Guide - pSeries AIX System Administration
11.3.2 Changing an exported file system
This section explains how you can change an exported NFS.
Changing an exported NFS directory using SMIT
The following procedure will guide you through changing an exported file system
using SMIT.
1. Unexport the file system on the CRoom server by entering:
exportfs -u /dirname
where /dirname is the name of the file system you want to change. In this
case, /home3.
2. On the CRoom server, enter:
smitty chnfsexp
The resulting screen is shown in Figure 11-6.
3. Enter the appropriate path name in the PATHNAME of exported directory
field. In this case, /home3.
Figure 11-6 Change the Attributes of an Exported Directory
Make whatever changes you need then press Enter.
4. Exit SMIT.
Chapter 11. Network File System administration 321
5. Re-export the file system by entering:
exportfs /dirname
where /dirname is the name of the file system you just changed, in this case
/home3.
Changing an exported NFS directory using a text editor
The following procedure will guide you through changing an exported file system
using a text editor.
1. Unexport the file system by entering:
exportfs -u /dirname
where /dirname is the name of the file system you want to change, in this
case /home3.
2. Open the /etc/exports file with your favorite text editor.
3. Make whatever changes you want.
4. Save and close the /etc/exports file.
5. Re-export the file system by entering:
exportfs /dirname
where /dirname is the name of the file system you just changed, in this case
/home3.
11.3.3 Unmounting a mounted file system
To unmount an explicitly or automatically mounted NFS directory, enter umount
/directory or unmount /directory, for example:
umount /backup
The rmfs command can be used to remove any file systems you created.
11.4 NFS files, commands, and daemons reference
In this section, the key NFS files, commands, and daemons are defined.
11.4.1 List of NFS Files
The following is a list of key NFS files.
/etc/bootparams Lists servers that diskless clients can use for booting.
/etc/exports Lists the directories that can be exported to NFS clients.
322 IBM ^ Certification Study Guide - pSeries AIX System Administration
/etc/networks Contains information about networks on the Internet
network.
/etc/pcnfsd.conf Options for the rpc.pcnfsd daemon.
/etc/rpc Contains database information for Remote Procedure
Call (RPC) programs.
/etc/xtab Lists directories that are currently exported.
/etc/filesystems Lists all file systems that can potentially be mounted and
their mounting configuration.
List of NFS commands
The following is a list of NFS Commands.
chnfs Starts a specified number of biod and nfsd daemons.
mknfs Configures the system to run NFS and starts NFS daemons.
nfso Configures NFS network options.
automount Mounts an NFS automatically.
chnfsexp Changes the attributes of an NFS-exported directory.
chnfsmnt Changes the attributes of an NFS-mounted directory.
exportfs Exports and unexports directories to NFS clients.
lsnfsexp Displays the characteristics of directories that are exported with
NFS.
lsnfsmnt Displays the characteristics of mounted NFS systems.
mknfsexp Exports a directory using NFS.
mknfsmnt Mounts a directory using NFS.
rmnfs Changes the configuration to stop the NFS daemons.
rmnfsexp Removes NFS-exported directories from a server's list of
exports.
rmnfsmnt Removes NFS-mounted file systems from a client's list of
mounts.
List of NFS daemons
The following is a list of NFS Locking daemons.
/usr/sbin/rpc.lockd Processes lock requests through the RPC package.
/usr/sbin/rpc.statd Provides crash-and-recovery functions for the locking
services on NFS.
Chapter 11. Network File System administration 323
The following is a list of NFS Network Service daemons and utilities.
/usr/sbin/biod Sends the client's read and write requests to the server.
The biod daemon is SRC controlled.
/usr/sbin/rpc.mountd Answers requests from clients for file system mounts.
The mountd daemon is SRC controlled.
/usr/sbin/nfsd Starts the daemons that handle a client's request for file
system operations. nfsd is SRC controlled.
/usr/sbin/nfsstat Displays information about a machine's ability to receive
calls.
/usr/sbin/portmap Maps RPC program numbers to Internet port numbers.
portmap is inetd Controlled.
/usr/bin/rpcgen Generates C code to implement an RPC protocol.
/usr/bin/rpcinfo Reports the status of RPC servers.
/usr/sbin/rpc.rstatd Returns performance statistics obtained from the kernel.
/usr/bin/showmount Displays a list of all clients that have mounted remote file
systems.
/usr/sbin/rpc.pcnfsd Handles service requests from PC-NFS clients.
11.5 NFS problem determination
Troubleshooting NFS problems involves a strategy for tracking NFS problems,
recognizing NFS-related error messages, and selecting the appropriate
solutions. When tracking down an NFS problem, isolate each of the three main
points of failure to determine which is not working: The server, the client, or the
network itself.
11.5.1 Identifying NFS problems checklist
If a client is having NFS trouble, perform the following tasks:
1. Verify that the network connections are functioning properly.
2. Verify that the inetd, portmap, and biod daemons are running on the client
(see Section 11.3.1, “Getting the Current Status of the NFS Daemons” on
page 319).
3. Verify that a valid mount point exists on the client system for the file system to
be mounted. For more information, see “Establishing predefined NFS
mounts” on page 313.
324 IBM ^ Certification Study Guide - pSeries AIX System Administration
4. Verify that the server is up and running, by executing the following command
at the shell prompt of the client machine:
/usr/bin/rpcinfo -p server_name
where server_name is the name of the server being verified.
If the server is up, a list of programs, versions, protocols, and port numbers is
displayed similar to the following:
program vers proto port
100000 2 tcp 111 portmapper
100000 2 udp 111 portmapper
100005 1 udp 1025 mountd
100001 1 udp 1030 rstatd
100001 2 udp 1030 rstatd
100001 3 udp 1030 rstatd
100002 1 udp 1036 rusersd
100002 2 udp 1036 rusersd
100008 1 udp 1040 walld
100012 1 udp 1043 sprayd
100005 1 tcp 694 mountd
100003 2 udp 2049 nfs
100024 1 udp 713 status
100024 1 tcp 715 status
100021 1 tcp 716 nlockmgr
100021 1 udp 718 nlockmgr
100021 3 tcp 721 nlockmgr
100021 3 udp 723 nlockmgr
100020 1 udp 726 llockmgr
100020 1 tcp 728 llockmgr
100021 2 tcp 731 nlockmgr
If a similar response is not returned, log in to the server at the server console
and check the status of the NFS daemons by following the instructions in
Section 11.3.1, “Getting the Current Status of the NFS Daemons” on
page 319.
Chapter 11. Network File System administration 325
5. Verify that the mountd, portmap, and nfsd daemons are running on the NFS
server by entering the following commands at the client shell prompt:
– /usr/bin/rpcinfo -u server_name mount.
As shown in the following example:
# /usr/bin/rpcinfo -u CRoom mount
program 100005 version 1 ready and waiting
program 100005 version 2 ready and waiting
program 100005 version 3 ready and waiting
#
– /usr/bin/rpcinfo -u server_name portmap.
As shown in the following example:
# /usr/bin/rpcinfo -u CRoom portmap
program 100000 version 2 ready and waiting
program 100000 version 3 ready and waiting
program 100000 version 4 ready and waiting
#
– /usr/bin/rpcinfo -u server_name nfs.
As shown in the following example:
# /usr/bin/rpcinfo -u CRoom nfs
program 100003 version 2 ready and waiting
program 100003 version 3 ready and waiting
#
The program numbers correspond to the commands, respectively, as shown
in step 4. If a similar response is not returned, log in to the server at the server
console and check the status of the daemons by following the instructions in
Section 11.3.1, “Getting the Current Status of the NFS Daemons” on
page 319.
6. Verify that the /etc/exports file on the server lists the name of the file system
that the client wants to mount and that the file system is exported. Do this by
entering the command:
showmount -e server_name
This command will list all the file systems currently exported by the
server_name.
11.5.2 Checking network connections
If the biod daemons are working, check the network connections. The nfsstat
command determines whether you are dropping packets. Use the nfsstat -c
and nfsstat -s commands to determine if the client or server is retransmitting
large blocks. Retransmissions are always a possibility due to lost packets or busy
servers. A retransmission rate of 5 percent is considered high.
326 IBM ^ Certification Study Guide - pSeries AIX System Administration
The probability of retransmissions can be reduced by changing the
communication adapter transmit queue parameters (xmt_que_size), or no
settings, to name two. SMIT or the chdev and no commands can be used to
change these parameters.
11.5.3 NFS error messages
The following sections explain error codes that can be generated while using
NFS.
Hard-mounted and soft-mounted file problems
When the network or server has problems, programs that access hard-mounted
remote files fail differently from those that access soft-mounted remote files.
If a server fails to respond to a hard-mount request, NFS prints the message:
NFS server hostname not responding, still trying
If a server fails to respond to a soft-mount request, NFS prints the message:
Connection timed out
Bad sendreply error message
Insufficient transmit buffers on your network can cause the following error
message:
nfs_server: bad sendreply
To increase transmit buffers, use the SMIT fast path smitty commodev. Then
select your adapter type and increase the number of transmit buffers.
Server not responding
Use the procedure in Section 11.5.1, “Identifying NFS problems checklist” on
page 323 to troubleshoot this error. The error usually occurs if the NFS daemons
have not been started or have been stopped. If the mountd or the nfsd daemons
were not started or were stopped on the server, then when a client tries to mount
an exported file system, an 1831-010 error message is displayed.
For example, if the rpc.mountd daemon dies after starting, and this error is
received at a client machine, then do the following:
1. Telnet to the server and log in as root.
2. cd to the /etc directory
3. Enter stopsrc -g nfs.
4. Enter stopsrc -s portmap.
Chapter 11. Network File System administration 327
5. Enter rm -rf state sm sm.bak xtab rmtab.
6. Enter startsrc -s portmap.
7. Enter startsrc -g nfs.
8. Enter exportfs -a.
9. showmount -e servername.
The rm -rf command clears the mountd files that may be too large for mountd to
handle. If this procedure does not work, then refer to Section 11.5, “NFS problem
determination” on page 323.
Remote mounting errors
The following list provides common mounting errors and their probable causes.
A remote mounting process can fail in several ways. The error messages
associated with mounting failures are as follows:
1.
mount: ... already mounted
The file system that you are trying to mount is already mounted.
2.
mount: ... not found in /etc/filesystems
The specified file system or directory name cannot be matched.
If you issue the mount command with either a directory or file system name
but not both, the command looks in the /etc/filesystems file for an entry whose
file system or directory field matches the argument. If the mount command
finds an entry, such as the following:
/danger.src:
dev=/usr/src
nodename = danger
type = nfs
mount = false
then it performs the mount as though you had entered the following at the
command line:
/usr/sbin/mount -n danger -o rw,hard /usr/src /danger.src
3. If you receive the following message:
mount... not in hosts database
a. On a network without Network Information Service (NIS), this message
indicates that the host specified to the mount command is not in the
/etc/hosts file. On a network running NIS, the message indicates that NIS
could not find the host name in the /etc/hosts database or that the NIS
ypbind daemon on your machine has terminated. If the /etc/resolv.conf file
328 IBM ^ Certification Study Guide - pSeries AIX System Administration
exists, so that a name server is being used for host name resolution, there
may be a problem in the named database.
Check the spelling and the syntax in your mount command. If the
command is correct, and your network does not run NIS, and you only get
this message for this host name, check the entry in the /etc/hosts file.
b. If your network is running NIS, make sure that the ypbind daemon is
running by entering the following at the command line:
ps -ef | grep ypbind
You should see an entry for the ypbind daemon. Try using the rlogin
command to log in remotely to another machine, or use the rcp command
to remote-copy something to another machine. If this also fails, your
ypbind daemon is probably stopped or hung.
If you only get this message for this host name, you should check the
/etc/hosts entry on the NIS server.
4.
mount: ... server not responding: port mapper failure - RPC timed out
Either the server you are trying to mount from is down, or its port mapper is
stopped or hung. Try restarting the inetd, portmap, and ypbind daemons.
If you cannot log in to the server remotely with the rlogin command, but the
server is up, you should check the network connection by trying to log in
remotely to some other machine. You should also check the server's network
connection.
5.
1831-019 mount: ... server not responding: program not registered
This means that the mount command got through to the port mapper, but the
rpc.mountd NFS mount daemon was not registered.
6.
mount: access denied...
Your machine name is not in the export list for the file system you are trying to
mount from the server.
You can get a list of the server's exported file systems by running the following
command at the command line:
showmount -e host_name
If the file system you want is not in the list, or your machine name or netgroup
name is not in the user list for the file system, log in to the server and check
the /etc/exports file for the correct file system entry. A file system name that
appears in the /etc/exports file, but not in the output from the showmount
command, indicates a failure in the mountd daemon. Either the daemon could
not parse that line in the file, it could not find the directory, or the directory
name was not a locally mounted directory. If the /etc/exports file looks correct
and your network runs NIS, check the server's ypbind daemon. It may be
stopped or hung.
Chapter 11. Network File System administration 329
7.
mount: ...: Permission denied
This message is a generic indication that some part of authentication failed
on the server. It may be that, as in the previous example, you are not in the
export list, the server could not recognize your machine's ypbind daemon, or
that the server does not accept the identity you provided.
Check the server's /etc/exports file and, if applicable, the ypbind daemon. In
this case, you can just change your host name with the hostname command
and retry the mount command.
8.
mount: ...: Not a directory
Either the remote path or the local path is not a directory. Check the spelling
in your command, and try to run it on both the remote and local paths.
9.
mount: ...: You are not allowed
You must have root authority or be a member of the system group to run the
mount command on your machine, because it affects the file system for all
users on that machine. NFS mounts and unmounts are only allowed for root
users and members of the system group.
11.6 Quiz
The following certification assessment question helps verify your understanding
of the topics discussed in this chapter.
1. An AIX system administrator decides to experiment with NFS. She exports
/home and /var, two file systems from a system called
pluto. The system
administrator now is on system called
mars, another AIX machine on the
same subnet as pluto. She now wishes to mount the exported file systems
from pluto onto mars. Which of the following commands will she use to view
the export list of 'pluto'?
A. exportlist pluto
B. rpcinfo -p pluto
C. showmount -e mars
D. showmount -e pluto
330 IBM ^ Certification Study Guide - pSeries AIX System Administration
The following are additional questions created by the authors to further test your
understanding of the topics.
1. A system administrator has been working on a project for the last couple of
months that requires writing different scripts on Server A. These scripts,
which have been run nightly, have been collecting data within log files in a
journaled file system called /project22. The system administrator would now
like to access this JFS from a remote server called Server B.
The system administrator has issued the command lssrc -g nfs and
discovered that the daemons are inoperative on Server A. Which of the
following actions should be performed to correct this situation?
A. Run the nfs.start command.
B. Run the startsrc -g nfs command.
C. Run the refresh -s nfsd command.
D. Log out and then log back into the system.
2. The same scenario from question one still applies.
Which of the following actions should be performed by the system
administrator to give Server B access to Server A's file system?
A. Run the chfs command on Server A.
B. Run the chfs command on Server B.
C. Run the exportfs command on Server A.
D. Run the exportfs command on Server B.
11.6.1 Answers
The following answer is for the assessment quiz questions.
1. D
The following answers are for the additional quiz questions.
1. B
2. C
11.7 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
Chapter 11. Network File System administration 331
Figure 11-7 Exhibit for NFS Exercises
1. You are required to recreate the environment in Figure 11-7. Take into
consideration the following:
– Client A and Client B are allowed access to the /finaldata directory.
– /data and /accdata are predefined mounts. Use a text editor to create the
/data mount in the /etc/filesystems file.
– /finaldata is an explicit mount.
– /accfinal is an automatic mount.
– On Client A /data and /accdata are mounted over mount point /user/data
and /user/accdata, respectively.
2. Determine the availability of NFS on each system.
3. From Client A, look at the directories exported on Server A and B,
respectively.
4. Unexport /accfinal from Server B. Refresh the NFS daemons on Server B.
5. Unmount /finaldata from Client B.
6. Disallow Client A access to /finaldata on Server A.
7. Determine all automatically mounted file systems.
8. Stop NFS daemon on Server A. From Client A, try to access /data on Server
A. Make note of any messages displayed. Restart the NFS daemons on
Server A. Retry accessing the /data export from Client A.
Server A
Server B
Client A
Client B
Exports
/data
/finaldata
Exports
/accdata
/accfinal
/finaldata
/data
/accdata
/accfinal
Mounts
Mounts
332 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 333
Chapter 12. System performance
For any system, continued customer satisfaction and purchasing decisions
depend strongly on performance. Part of the job of the system administrator is
performance analysis: To understand the system behavior and identify the usage
of resources.
This section provides information on concepts, tools, and techniques for
assessing and tuning the performance of AIX on RS/6000 systems. Topics
covered include assessment of CPU use, memory use, disk I/O, and
communications I/O. The concepts, tools, and techniques discussed in this
section are not intended to be a total list, and, as such, you are encouraged to
seek additional information from the appropriate AIX product documentation.
12
334 IBM ^ Certification Study Guide - pSeries AIX System Administration
12.1 System dynamics and workload
An accurate and complete definition of the system's workload is critical to
predicting or understanding its performance. A difference in workload can cause
far more variation in the measured performance of a system than differences in
CPU clock speed or RAM size. The workload definition must include not only the
type and rate of requests to the system but also the exact software packages and
in-house application programs to be executed.
Whenever possible, normal usage of existing applications should be observed to
get authentic, real-world measurements of the rates at which users interact with
their workstations or terminals.
Make sure that you include the work load that your system is doing behind the
scenes. For example, if your system contains file systems that are NFS-mounted
and frequently accessed by other systems, handling those accesses is probably
a significant fraction of the overall workload even though your system is not
officially a
server.
12.1.1 System dynamics
It is not enough to have the most efficient programs. In many cases, the actual
programs being run are outside of the control of the person who is responsible for
meeting the organization's performance objectives. Once the application
programs have been acquired or implemented as efficiently as possible, further
improvement in the overall performance of the system becomes a matter of
system tuning. The main components that are subject to system-level tuning are:
Fixed disk The Logical Volume Manager (LVM) controls the
placement of file systems and paging spaces on the disk,
which can significantly affect the amount of seek latency
the system experiences. The disk device drivers control
the order in which I/O requests are acted on.
Real memory The Virtual Memory Manager (VMM) controls the pool of
free real-memory frames and determines when and from
whom to steal frames to replenish the pool.
Running thread The scheduler determines which dispatchable entity
should receive control next. (In AIX Version 4, the
dispatchable entity changes from a process to a thread.)
Communications I/O Depending on the type of workload and the type of
communications link, it may be necessary to tune one or
more of the communications device drivers, TCP/IP, or
NFS.
Chapter 12. System performance 335
12.1.2 Classes of workloads
Workloads tend to fall naturally into a small number of classes. The types that
follow are sometimes used to categorize systems. However, since a single
system is often called upon to process multiple classes,
workload seems more
apt in the context of performance.
Workstation A workload that consists of a single user submitting work through
the native keyboard and receiving results on the native display of
the system. Typically, the highest-priority performance objective
of such a workload is minimum response time to the user's
requests.
Multiuser A workload that consists of a number of users submitting work
through individual terminals. Typically, the performance
objectives of such a workload are either to maximize system
throughput while preserving a specified worst-case response
time or to obtain the best possible response time for a fairly
constant workload.
Server A workload that consists of requests from other systems. For
example, a file-server workload is mostly disk read/write
requests. In essence, it is the disk-I/O component of a multiuser
workload (plus NFS or DFS activity); so, the same objective of
maximum throughput within a given response-time limit applies.
Other server workloads consist of compute-intensive programs,
database transactions, print jobs, and so on.
When a single system is processing workloads of more than one type, there must
be a clear understanding between the users and the performance analyst as to
the relative priorities of the possibly conflicting performance objectives of the
different workloads.
12.1.3 General performance and availability guidelines
There are some basic guidelines that can help with the configuration of systems,
depending on their intended use. These are outlined briefly as follows:
Multi-threaded applications benefit the most from multiple CPUs.
I/O intensive applications benefit the most from multiple I/O adapters and
many disk drives.
Additional memory is never disadvantageous.
Data availability can be increased by using hardware or software mirroring.
When intending to have a backup server for use in case of a failure in the
primary server, it should be as identical to the primary server as possible,
preferably an exact duplicate.
336 IBM ^ Certification Study Guide - pSeries AIX System Administration
12.2 Overview of system performance
The AIX Base Operating System contains a number of monitoring and tuning
tools that have historically been part of UNIX systems or are required to manage
the implementation-specific features of AIX. The BOS functions and commands
that are most important to performance analysts are:
iostat Reports CPU and I/O statistics.
vmstat Reports virtual-memory activity and other system statistics.
netstat Displays the contents of network-related data structures.
ps Displays the status of processes.
lsattr Displays the attributes of devices.
lslv Displays information about a logical volume or the logical volume
allocations of a physical volume.
nfsstat Displays statistics about Network File System (NFS) and Remote
Procedure Call (RPC) activity.
nice Runs a command at higher- or lower-than-normal priority.
no Displays or sets network options.
renice Changes the priority of one or more processes.
reorgvg Reorganizes the physical-partition allocation within a volume group.
sar Collects and reports or records system-activity information.
schedtune Sets parameters for CPU scheduler and Virtual Memory Manager
processing.
svmon Captures and analyzes a snapshot of virtual memory.
time Prints the elapsed execution time and the user and system
processing time attributed to a command.
tprof Reports CPU usage for individual programs and the whole system.
trace Records and reports selected system events.
In the following section, a subset of these functions and commands is discussed.
12.3 Base Operating System tools
The following commands are the focus throughout this section.
vmstat
iostat
Chapter 12. System performance 337
netstat
sar
12.3.1 Using the vmstat command
The vmstat command syntax is as follows:
vmstat [ -f ] [ -i ] [ -s ] [ PhysicalVolume ... ] [ Interval [ Count ] ]
The vmstat command reports statistics about kernel threads, virtual memory,
disks, traps, and CPU activity. Reports generated by the vmstat command can
be used to balance system load activity. These system-wide statistics (among all
processors) are calculated either as averages for values expressed as
percentages, or as sums.
The PhysicalVolume parameter can be used to specify one to four names.
Transfer statistics are given for each specified drive in the order specified. This
count represents logical and physical requests to the physical device. It does not
imply an amount of data that was read or written. Several logical requests can be
combined into one physical request.
If the vmstat command is invoked without flags, the report contains a summary of
the virtual memory activity since system startup. If the -f flag is specified, the
vmstat command reports the number of forks since system startup. The
PhysicalVolume parameter specifies the name of the physical volume.
The Interval parameter specifies the amount of time in seconds between each
report. The first report contains statistics for the time since system startup.
Subsequent reports contain statistics collected during the interval since the
previous report. If the Interval parameter is not specified, the vmstat command
generates a single report and then exits.
The Count parameter can only be specified with the Interval parameter. If the
Count parameter is specified, its value determines the number of reports
generated and the number of seconds apart. If the Interval parameter is specified
without the Count parameter, reports are continuously generated. A Count
parameter of zero (0) is not allowed.
The kernel maintains statistics for kernel threads, paging, and interrupt activity,
which the vmstat command accesses. The disk input/output statistics are
maintained by device drivers. For disks, the average transfer rate is determined
by using the active time and number of transfers information. The percent active
time is computed from the amount of time the drive is busy during the report.
338 IBM ^ Certification Study Guide - pSeries AIX System Administration
Table 12-1 provides the key flags for the vmstat command:
Table 12-1 Key flags for the vmstat command
Examples
The following are some examples using the vmstat command.
1. To display a summary of the statistics since boot, enter vmstat. A sample
output follows:
2. To display five summaries at 2-second intervals, enter vmstat 2 5. A sample
output follows:
The first summary (line one of the report) contains statistics for the time since
boot.
Note: Both the -f and -s flags can be entered on the command line, but the
system will only accept the first flag specified and will override the second
flag.
Flag Description
-f Reports the number of forks since system startup.
-i Displays the number of interrupts taken by each device since system
startup.
-s Writes to standard output the contents of the sum structure, which
contains an absolute count of paging events since system
initialization. The -s option is exclusive of the other vmstat
command options.
# vmstat
kthr memory page faults cpu
----- ----------- ------------------------ ------------ -----------
r b avm fre re pi po fr sr cy in sy cs us sy id wa
0 0 19046 1554 0 0 0 0 0 0 117 310 30 0 1 99 1
#
# vmstat 2 5
kthr memory page faults cpu
----- ----------- ------------------------ ------------ -----------
r b avm fre re pi po fr sr cy in sy cs us sy id wa
0 0 19097 1498 0 0 0 0 0 0 117 310 30 0 1 99 1
0 0 19097 1498 0 0 0 0 0 0 121 168 34 0 1 99 0
0 0 19097 1498 0 0 0 0 0 0 126 118 34 0 0 99 0
0 0 19097 1498 0 0 0 0 0 0 121 118 38 0 0 99 0
0 0 19097 1498 0 0 0 0 0 0 122 121 34 0 0 99 0
#
Chapter 12. System performance 339
3. To display a summary of the statistics since boot, including statistics for
logical disks hdisk0 and hdisk1, enter: vmstat hdisk0 hdisk1. A sample
output follows:
4. To display fork statistics, enter: vmstat -f. A sample output follows:
# vmstat -f
13887 forks
#
5. To display the count of various events, enter: vmstat -s. A sample output
follows:
# vmstat hdisk0 hdisk1
kthr memory page faults cpu disk xfer
----- ----------- ------------------------ ------------ ----------- -----------
r b avm fre re pi po fr sr cy in sy cs us sy id wa 1 2 3 4
0 0 18461 3284 0 0 0 0 0 0 117 310 30 0 1 99 1 0 0
#
# vmstat -s
2205645 total address trans. faults
46745 page ins
135567 page outs
7088 paging space page ins
16737 paging space page outs
0 total reclaims
950333 zero filled pages faults
12659 executable filled pages faults
233034 pages examined by clock
15 revolutions of the clock hand
48272 pages freed by the clock
27557 backtracks
0 lock misses
10 free frame waits
0 extend XPT waits
38657 pending I/O waits
163907 start I/Os
163907 iodones
12734979 cpu context switches
49535570 device interrupts
0 software interrupts
0 traps
130379165 syscalls
#
340 IBM ^ Certification Study Guide - pSeries AIX System Administration
vmstat report output
Table 12-2 contains the column headings and their description for vmstat output.
Table 12-2 vmstat output parameters
Parameter Description
Kthr: Kernel thread state
r Number of kernel threads waiting in run queue. This value is zero in an
idle system and higher in a CPU bound system.
b Number of kernel threads waiting on the wait queue (awaiting resource,
awaiting input/output).
Memory: Usage of virtual and real memory
avm Active virtual pages, that is, the total number of pages allocated in page
space. A high value is not an indicator of poor performance.
fre Size of the free list RAM pages
Page: Page faults and paging activity
re Pager input/output list
pi Pages paged in from paging space
po Pages paged out to paging space.
fr Pages freed (page replacement)
sr Pages scanned by page-replacement algorithm
cy Clock cycles used by page-replacement algorithm
Faults: Trap and interrupt rate averages per second
in Device interrupts
sy System calls
cs Kernel thread context switches
CPU: % usage of CPU time
us User time
sy System time
id CPU idle time
wa CPU cycles to determine that the current process is wait, and there is
pending disk input/output.
Chapter 12. System performance 341
12.3.2 Using the iostat command
The iostat command syntax is as follows:
iostat [ -d | -t ] [ PhysicalVolume ... ] [ Interval [ Count ] ]
The iostat command is used for monitoring system input/output device loading
by observing the time the physical disks are active in relation to their average
transfer rates. The iostat command generates reports that can be used to
determine what changes should be made to the system configuration to better
balance the input/output load between physical disks.
The first report generated by the iostat command provides statistics concerning
the time since the system was booted.
Each subsequent report covers the time since the previous report. All statistics
are reported each time the iostat command is run. The report consists of a TTY
and CPU header row followed by a row of TTY and CPU statistics. On
multiprocessor systems, CPU statistics are calculated system-wide as averages
among all processors. A disks header row is displayed followed by a line of
statistics for each disk that is configured. If the PhysicalVolume parameter is
specified, only those names specified are displayed.
If the PhysicalVolume parameter is specified:
One or more physical volumes can be specified.
The TTY and CPU reports are displayed.
The disk report contains statistics for the specified drives.
The first character in the PhysicalVolume parameter cannot be numeric.
The Interval parameter specifies the amount of time in seconds between each
report. The first report contains statistics for the time since system startup (boot).
Each subsequent report contains statistics collected during the interval since the
previous report.
Disk: Provides the number of transfers per second to the specified physical
volumes that occurred in the sample interval
Note: A large portion of real memory is utilized as a cache for file system
data. It is not unusual for the size of the free list to remain small.
Parameter Description
342 IBM ^ Certification Study Guide - pSeries AIX System Administration
The Count parameter can be specified in conjunction with the Interval parameter.
If the Count parameter is specified, the value of count determines the number of
reports generated at Interval seconds apart. If the Interval parameter is specified
without the Count parameter, the iostat command generates reports
continuously.
The iostat command is useful in determining whether a physical volume is
becoming a performance bottleneck and if there is potential to improve the
situation. The % utilization field for the physical volumes indicates how evenly the
file activity is spread across the drives. A high percentage utilization on a
physical volume is a clear indication that there may be contention for this
resource. Since the CPU utilization statistics are also available with the iostat
report, the percentage of time the CPU is in I/O wait can be determined at the
same time. Consider distributing data across drives if the I/O wait time is
significant, and the disk utilization is not evenly distributed across volumes.
Table 12-3 provides a list of common iostat command flags.
Table 12-3 Key flags for the iostat command
Examples
The following are examples of the iostat command usage.
1. To display a single history since boot report for all tty, CPU, and Disks, enter:
Note: Some amount of system resources are consumed in maintaining disk
I/O history for the iostat command. Use the sysconfig subroutine or SMIT
to stop history accounting.
Flag Description
-d The -d option is exclusive of the -t option and displays only the disk
utilization report.
-t The -t option is exclusive of the -d option and displays only the TTY
and CPU usage reports.
#iostat
tty: tin tout avg-cpu: % user % sys % idle % iowait
0.1 32.9 5.9 17.0 32.3 44.8
Disks: % tm_act Kbps tps Kb_read Kb_wrtn
hdisk1 3.7 34.5 1.9 4664 128
hdisk0 46.5 526.3 40.2 68116 5048
cd0 0.0 0.0 0.0 0 0
#
Chapter 12. System performance 343
2. To display a continuous disk report at two second intervals for the disk with
the name hdisk1, enter:
iostat -d hdisk1 2
3. To display six reports at two second intervals for the disk with the logical name
hdisk1, enter:
iostat -d hdisk1 2 6
4. To display six reports at two second intervals for all disks, enter:
iostat -d 2 6
5. To display six reports at two second intervals for three disks named disk1,
disk2, disk3, enter:
iostat -d disk1 disk2 disk3 2 6
iostat report output
The iostat command generates two types of reports, the tty and CPU Utilization
report and the Disk Utilization report. The meaning of the output parameters is
shown in Table 12-4.
Table 12-4 iostat output parameters
Parameter Description
TTY and CPU Utilization Report:
The first report generated by the iostat command is the TTY and CPU Utilization
Report. For multiprocessor systems, the CPU values are global averages among all
processors. Also, the I/O wait state is defined system-wide and not per processor.
This information is updated at regular intervals by the kernel (typically sixty times
per second). The TTY report provides a collective account of characters per second
received from all terminals on the system as well as the collective count of
characters output per second to all terminals on the system. The report gives the
following information:
tin Shows the total number of characters read by the system for all TTYs.
tout Shows the total number of characters written by the system to all
TTYs.
% user Shows the percentage of CPU utilization that occurred while executing
at the user level (application).
% sys Shows the percentage of CPU utilization that occurred while executing
at the system level (kernel).
344 IBM ^ Certification Study Guide - pSeries AIX System Administration
For large system configurations where a large number of disks are configured,
the system can be configured to avoid collecting physical disk input/output
statistics when the iostat command is not executing. If the system is configured
in the above manner, the first Disk report displays the message Disk History
Since Boot Not Available instead of the disk statistics. Subsequent interval
reports generated by the iostat command contain disk statistics collected during
the report interval. Any TTY and CPU statistics after boot are unaffected. If a
system management command is used to re-enable disk statistics, the first
iostat command report displays activity from the interval starting at the point
that disk input/output statistics were enabled.
% idle Shows the percentage of time that the CPU or CPUs were idle, and
the system did not have an outstanding disk I/O request.
% iowait Shows the percentage of time that the CPU or CPUs were idle during
which the system had an outstanding disk I/O request. This value may
be slightly inflated if several processors are idling at the same time.
This is an unusual occurance.
Disk Utilization Report:
The second report generated by the iostat command is the Disk Utilization Report.
The disk report provides statistics on a per physical disk basis. The report has a
format similar to the following:
% tm_act Indicates the percentage of time the physical disk was active
(bandwidth utilization for the drive).
Kbps Indicates the amount of data transferred (read or written) to the drive
in KB per second.
tps Indicates the number of transfers per second that were issued to the
physical disk. A transfer is an I/O request to the physical disk. Multiple
logical requests can be combined into a single I/O request to the disk.
A transfer is of indeterminate size.
Kb_read The total number of KB read.
Kb_wrtn The total number of KB written.
Parameter Description
Chapter 12. System performance 345
12.3.3 Using the netstat command
The netstat command syntax is as follows:
To display active sockets for each protocol or routing table information:
/bin/netstat [ -n ] [ { -A -a } | { -r -i -I Interface } ] [ -f AddressFamily ]
[ -p Protocol ] [ Interval ] [ System ]
To display the contents of a network data structure:
/bin/netstat [ -m | -s | -u | -v ] [ -f AddressFamily ] [ -p Protocol ]
[ Interval ] [ System ]
To display the packet counts throughout the communications subsystem:
/bin/netstat -D
The netstat command (Table 12-5) symbolically displays the contents of various
network-related data structures for active connections. The Interval parameter,
specified in seconds, continuously displays information regarding packet traffic
on the configured network interfaces. The Interval parameter takes no flags. The
System parameter specifies the memory used by the current kernel. Unless you
are looking at a dump file, the System parameter should be /unix.
Table 12-5 Key flags for the netstat command
Flag Description
-n Shows network addresses as numbers. When this flag is not
specified, the command interprets addresses where possible and
displays them symbolically.
-r Shows the routing tables. When used with the -s flag, the -r flag
shows routing statistics.
-s Shows statistics for each protocol.
Note: In the statistics output, a N/A displayed in a field value indicates the
count is not applicable. For the NFS/RPC statistics, the number of incoming
packets that pass through RPC are the same packets that pass through NFS;
so, these numbers are not summed in the NFS/RPC Total field, thus, the N/A.
NFS has no outgoing packet or outgoing packet drop counters specific to NFS
and RPC. Therefore, individual counts have a field value of N/A, and the
cumulative count is stored in the NFS/RPC Total field.
The collision count for Ethernet interfaces is not supported.
346 IBM ^ Certification Study Guide - pSeries AIX System Administration
Examples
The following are examples of netstat command usage.
To display the routing table, use the command:
# netstat -r
Routing tables
Destination Gateway Flags Refs Use If PMTU Exp Groups
Route Tree for Protocol Family 2 (Internet):
default itso240 UGc 0 0 tr0 - -
9.3.240/24 server1 U 39 349098 tr0 - -
127/8 localhost U 4 696 lo0 - -
Route Tree for Protocol Family 24 (Internet v6):
::1 ::1 UH 0 0 lo0 16896 -
#
To display the routing table with network addresses as numbers, use the
command:
# netstat -rn
Routing tables
Destination Gateway Flags Refs Use If PMTU Exp Groups
Route Tree for Protocol Family 2 (Internet):
default 9.3.240.1 UGc 0 0 tr0 - -
9.3.240/24 9.3.240.56 U 36 349117 tr0 - -
127/8 127.0.0.1 U 4 696 lo0 - -
Route Tree for Protocol Family 24 (Internet v6):
::1 ::1 UH 0 0 lo0 16896 -
#
To display the routing statistics use the command:
# netstat -r -s
routing:
0 bad routing redirect
0 dynamically created route
0 new gateway due to redirects
0 destination found unreachable
0 use of a wildcard route
#
netstat output report
The default display for active sockets shows the following items:
Local and remote addresses
Chapter 12. System performance 347
Send and receive queue sizes (in bytes)
Protocol
Internal state of the protocol
Internet address formats are of the form host.port or network.port if a socket's
address specifies a network but no specific host address. The host address is
displayed symbolically if the address can be resolved to a symbolic host name
while network addresses are displayed symbolically according to the
/etc/networks file.
NS addresses are 12-byte quantities consisting of a 4-byte network number, a
6-byte host number, and a 2-byte port number, all of which are stored in network
standard format. For VAX architecture, these are word and byte reversed; for the
Sun systems, they are not reversed.
If a symbolic name for a host is not known, or if the -n flag is used, the address is
printed numerically according to the address family. Unspecified addresses and
ports appear as an * (asterisk).
Interface Display (netstat -i)
The interface display format provides a table of cumulative statistics for the
following items:
Errors
Collisions
The collision count for Ethernet interfaces is not supported.
Packets transferred
The interface display also provides the:
interface name,
number, and
address, as well as
the maximum transmission units (MTUs).
Routing Table Display (netstat -r)
The routing table display format indicates the available routes and their statuses.
Each route consists of a destination host or network and a gateway to use in
forwarding packets.
The flags field of the routing table shows the state of the route:
U Up.
H The route is to a host rather than to a network.
348 IBM ^ Certification Study Guide - pSeries AIX System Administration
G The route is to a gateway.
D The route was created dynamically by a redirect.
M The route has been modified by a redirect.
L The link-level address is present in the route entry.
c Access to this route creates a cloned route. This field only applies to AIX
Version 4.2.1 or later.
W The route is a cloned route. This field only applies to AIX Version 4.2.1 or
later
Direct routes are created for each interface attached to the local host.
Gateway The gateway field for these entries shows the address of the
outgoing interface.
Refs Gives the current number of active uses for the route.
Connection-oriented protocols hold onto a single route for the
duration of a connection, while connectionless protocols obtain a
route while sending to the same destination.
Use Provides a count of the number of packets sent using that route.
PMTU Gives the Path Maximum Transfer Unit (PMTU). This field only
applies to AIX Version 4.2.1 or later.
Interface Indicates the network interfaces utilized for the route.
Exp Displays the time (in minutes) remaining before the route expires.
This field only applies to AIX Version 4.2.1 or later.
Groups Provides a list of group IDs associated with that route. This field
only applies to AIX Version 4.2.1 or later.
Netmasks Lists the netmasks applied on the system.
12.3.4 Additional performance related commands
The following commands are used to examine specific system areas, either to
complement the results from vmstat, iostat and netstat, or to provide more in
depth information. Detailed descriptions of these tools is outside the scope of this
chapter, but you should be aware of them.
The svmon command
The svmon command provides a more in-depth analysis of memory usage. It is
more informative, but also more intrusive, than the vmstat commands.
Chapter 12. System performance 349
The sar command
The sar command writes to standard output the contents of selected cumulative
activity counters in the operating system. You can use flags to select information
about specific system activities. Specifying no flags selects only system unit
activity, specifying the -A flag selects all activities.
The tprof command
The tprof command can be used over a time period to trace the activity of the
CPU. The CPU utilization is divided into kernel, user, shared, and other to show
how many clock timer ticks were spent in each respective address space.
The schedtune command
The schedtune command allows you to modify the default behavior of the
scheduling system for threads and processes, and should be used with extreme
care by experienced administrators. Do not manipulate the scheduler without
thorough knowledge of the scheduler mechanism.
12.4 Controlling resource usage
The following sections describe various methods to limit the consumption of
system resources.
12.4.1 Using the nice and renice commands
The nice and renice commands are used to change the priority of a process.
The nice command runs another command at a different priority, while the
renice command changes the priority of an already running process. The root
user can increase or decrease the priority of any process. Other users can only
decrease the priority of processes they own.
The following example shows the nice command running the cc command at a
lower priority:
# nice -n 15 cc -c *.c
The following example shows the renice command lowering the priority of
process ID 16304 by 5:
# renice -n 5 16304
350 IBM ^ Certification Study Guide - pSeries AIX System Administration
12.4.2 Workload Manager
The Workload Manager (WLM) allows the system administrator to divide
resources between jobs. WLM provides isolation between user communities with
very different system behaviors. This can prevent effective starvation of
workloads with certain characteristics, such as interactive or low CPU usage
jobs, by workloads with other characteristics, such as batch or high memory
usage jobs. CPU time, memory, and I/O bandwidth are managed separately,
therefore, different styles of applications can be managed.
AIX WLM delivers the basic ability to give system administrators more control
over how scheduler, Virtual Memory Manager (VMM), and device driver calls
allocate CPU, physical memory, and I/O bandwidth to classes-based user, group,
application path, process type, or application tags.
The AIX WLM is an operating system feature introduced in AIX Version 4.3.3.
12.5 Performance analysis
In this section, system performance is analyzed to determine whether a system
is CPU bound or memory bound. There is also a discussion on the idle time for
Symmetric Multiprocessors (SMP) and Uniprocessor (UP) systems.
The following are some terms used during this discussion.
CPU bound A system is said to be CPU-bound if the total system (sy) and
user (us) CPU usage is approaching 100 percent. This would
imply that idle time and wait time for CPU are approaching
zero.
Memory bound A system is memory-bound if some virtual memory is forced
out to disk, meaning the system is waiting on a relatively slow
disk instead of relatively fast RAM. This is indicated by a
non-zero value in the page-in (pi) and page-out (po) values.
12.5.1 Determining CPU-bound and memory bound systems
In this section, you will look at the sy and us columns for the CPU usage to
determine if the system was CPU-bound during the time the vmstat command
was gathering system information.
You need to obtain a preliminary look at the performance of the system as shown
in Figure 12-1.
Chapter 12. System performance 351
Figure 12-1 vmstat report of cpu-bound system
Remember that a system is CPU-bound if the total system and user CPU usage
approaches 100 percent.
For rows two through five, the system +user CPU usage are:
Row 2 =(66+31)%=97% and r = 2
Row 3 =(77+23)%=100% and r = 2
Row 4 =(60+40)%=100% and r = 4
Row 5 =(88+12)%=100% and r = 3
There are two indications that this system is CPU bound.
The CPU usage values tend towards 100 percent, and
The r values are nonzero indicating that the CPU has more work to perform.
This is mentioned previously, as an indicator for CPU activity, in “vmstat report
output” on page 340.
To determine if a system is memory bound, the pi and po columns are taken into
consideration. As defined in Section 12.5, “Performance analysis” on page 350,
a system is memory bound if the average page in rate (pi) for paging spaces and
the average page out rate (po) for paging spaces were non-zero.
12.5.2 Idle time calculations
Idle time calculations on a Symmetric Multiprocessor (SMP) and an
Uniprocessor system are the same. In an SMP environment, the output received
from the vmstat and iostat commands are a summary of the system wait and
idle time across all processors. You need only use the tools as laid out in the
previous sections and calculate the system idle time based on the output
received.
352 IBM ^ Certification Study Guide - pSeries AIX System Administration
When calculating total system idle time over an interval, both the percentage of
idle time (id), and the percentage of wait time (wa) are to be considered. Both
fields are obtained from the vmstat command output.
To calculate the time that the system is idle using the output from the vmstat
command, perform the following:
1. Calculate the average percentage idle time over the interval.
Given the following output from an SMP system, calculate the system idle
time from the command vmstat 900 4, that is, an output every 900 seconds or
(15 minutes) four times.
kthr memory page faults cpu
----- ----------- ------------------------ ------------ -----------
r b avm fre re pi po fr sr cy in sy cs us sy id wa
0 0 11015 205693 0 0 0 0 0 0 102 11 6 0 0 99 1
0 1 13014 203638 0 0 0 0 0 0 513 202 233 0 0 97 2
0 1 13903 202718 0 0 0 0 0 0 528 256 262 0 0 95 4
0 1 13008 203613 0 0 0 0 0 0 509 178 225 0 0 99 1
Average CPU Idle Time percentage = Sum (%Idle Times(id) + %wait)/ #
readings, therefore, the Average CPU Idle Time percentage = ((99+1) +
(97+2) + (95+4) + (99+1))/4 = 99.5%
2. Then calculate the Total CPU Idle Time in minutes.
These readings were obtained over one hour, therefore, total CPU Idle Time
for this system = 99.5% x 60 minutes = ~59 minutes
12.5.3 Calculating paging rate
Paging rate is the average number of page-ins and page-outs per CPU cycle.
If the pagein/pageout (pi/po) ratio is greater than one, it is indicating that for every
pagein there is at least one pageout and, therefore, points to high paging
activities. This system is, therefore, said to have a high paging rate.
Note: Total CPU Idle Time % = wait % + Idle Time %
Chapter 12. System performance 353
12.6 Quiz
The following certification assessment questions help verify your understanding
of the topics discussed in this chapter.
1. The finance department at the Widget Company needs a larger server. The
current server has 40 GB of hard drive space, two processors and 2 GB of
memory. The application is a fully multi-threaded process and is very I/O
intensive. What configuration should the company purchase to fix current
problems and plan for future expansion?
A. One 60 GB SCSI hard disk, 4 processors, and 2 GB of memory.
B. Two 20 GB SSA hard disks, 4 processors, and 4 GB of memory.
C. Two 20 GB SCSI hard disks, 2 processors, and 8 GB of memory.
D. Three 20 GB SSA hard disks, 4 processors, and 2 GB of memory.
2. The Widget Company is trying to implement disaster recovery procedures
and techniques. They currently have two daily backups taken of all data. In
the event that they need to restore data to another machine, what type of
machine would be ideal?
A. A slightly slower machine of the same type.
B. An exact duplicate of the original machine.
C. A slightly slower machine of the same type with less processors.
D. An exact duplicate of the original machine with less processors.
354 IBM ^ Certification Study Guide - pSeries AIX System Administration
The following are additional questions created by the authors to further test your
understanding of the topics.
1. A system administrator is experiencing performance problems and runs the
vmstat command. The output of vmstat is shown in the following exhibit.
procs memory page faults cpu
----- ----------- ------------------------ ------------ -----------
r b avm fre re pi po fr sr cy in sy cs us sy id wa
2 0 22534 1465 0 0 0 0 0 0 238 903 239 77 23 0 0
2 0 22534 1445 0 0 0 0 0 0 209 1142 205 72 28 0 0
2 0 22534 1426 0 0 0 0 0 0 189 1220 212 74 26 0 0
3 0 22534 1410 0 0 0 0 0 0 255 1704 268 70 30 0 0
2 1 22557 1365 0 0 0 0 0 0 383 977 216 72 28 0 0
What can be concluded from this output?
A. The machine is CPU bound.
B. The machine needs memory optimized.
C. The machine needs a FDDI card installed.
D. A user program is causing unnecessary paging.
2. A system administrator runs the vmstat command. The output of vmstat is
shown in the following exhibit (using a 15 minute interval).
kthr memory page faults cpu
----- ----------- ------------------------ ------------ -----------
r b avm fre re pi po fr sr cy in sy cs us sy id wa
2 0 9200 11027 0 0 0 0 0 0 103 52 14 14 16 0 69
2 1 9200 11027 0 0 0 0 0 0 207 251 29 12 11 0 67
3 1 9200 11027 0 0 0 0 0 0 207 120 29 9 11 0 80
5 1 9200 11027 0 0 0 0 0 0 206 120 29 13 5 0 79
4 1 9200 11027 0 0 0 0 0 0 207 131 32 9 8 0 72
Based on this output, what is the average CPU idle time as a percentage?
A. 45.5
B. 75.3
C. 44.04
D. 73.4
Chapter 12. System performance 355
12.6.1 Answers
The following answers are for the assessment quiz questions.
1. D
2. B
The following answers are for the additional quiz questions.
1. A
2. D
12.7 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Gather statistics using the vmstat, iostat, and netstat commands. Take a
look at your system performance.
2. Calculate your systems idle time (in minutes) and the paging rate.
3. Determine if your system is CPU bound or memory bound.
356 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 357
Chapter 13. User administration
This chapter discusses user administration that consists of creating and
removing user accounts, defining and changing user attributes, and the
important files referenced.
13
358 IBM ^ Certification Study Guide - pSeries AIX System Administration
13.1 Overview
Users are the primary agents on the system. Each user is required to log in to the
system. The user supplies the user name of an account and a password if the
account has one (on a secure system, all accounts either have passwords or are
invalidated). If the password is correct, the user is logged in to that account; the
user acquires the access rights and privileges of the account. The /etc/passwd
and /etc/security/passwd files maintain user passwords.
Groups are collections of users who can share access permissions for protected
resources. A group has an ID, and a group is composed of members and
administrators. The creator of the group is usually the first administrator. There
are three types of groups:
User group User groups should be made for people who
need to share files on the system, such as
people who work in the same department or
people who are working on the same project. In
general, create as few user groups as possible.
System administrator groups System administrator groups correspond to the
SYSTEM group. SYSTEM group membership
allows an administrator to perform some system
maintenance tasks without having to operate
with root authority.
System-defined groups There are several system-defined groups. The
STAFF group is the default group for all
nonadministrative users created in the system.
You can change the default group by using the
chsec command to edit the
/usr/lib/security/mkuser.default file. The
SECURITY group is a system-defined group
having limited privileges for performing security
administration.
An attribute is a characteristic of a user or a group that defines the type of
functions that a user or a group can perform. These can be extraordinary
privileges, restrictions, and processing environments assigned to a user. Their
attributes control their access rights, environment, how they are authenticated,
and how, when, and where their accounts can be accessed. These attributes are
created from default values when a user is created through the mkuser
command. They can be altered by using the chuser command.
Some users and groups can be defined as administrative. These users and
groups can be created and modified only by the root user.
Chapter 13. User administration 359
13.2 User administration related commands
The following are a few of the important commands used for user administration:
mkuser Creates a new user.
passwd Creates or changes the password of a user.
chuser Changes user attributes (except password).
lsuser Lists user attributes.
rmuser Removes a user and its attributes.
chsec Changes security related stanzas.
login Initiates a user session.
who Identifies the users currently logged in.
dtconfig Enables or disables the desktop autostart feature.
13.3 User administration related files
The following files are referenced while doing user administration:
/etc/security/environ Contains the environment attributes for users.
/etc/security/lastlog Contains the last login attributes for users.
/etc/security/limits Contains process resource limits for users.
/etc/security/user Contains extended attributes for users.
/usr/lib/security/mkuser.default Contains the default attributes for new users.
/usr/lib/security/mkuser.sys Customizes new user accounts.
/etc/passwd Contains the basic attributes of users.
/etc/security/passwd Contains password information.
/etc/security/login.cfg Contains configuration information for login
and user authentication.
/etc/utmp Contains the record of users logged into the
system.
/var/adm/wtmp Contains connect time accounting records.
/etc/security/failedlogin Records all failed login attempts.
/etc/motd Contains the message to be displayed every
time a user logs in to the system.
360 IBM ^ Certification Study Guide - pSeries AIX System Administration
/etc/environment Specifies the basic environment for all
processes.
/etc/profile Specifies additional environment settings for
all users.
$HOME/.profile Specifies environment settings for specific
user needs.
/etc/group Contains the basic attributes of groups.
/etc/security/group Contains the extended attributes of groups.
13.3.1 /etc/security/environ
The /etc/security/environ file is an ASCII file that contains stanzas with the
environment attributes for users. Each stanza is identified by a user name and
contains attributes in the Attribute=Value form with a comma separating the
attributes. Each line is ended by a new-line character, and each stanza is ended
by an additional new-line character. If environment attributes are not defined, the
system uses default values.
The mkuser command creates a user stanza in this file. The initialization of the
attributes depends upon their values in the /usr/lib/security/mkuser.default file.
The chuser command can change these attributes, and the lsuser command
can display them. The rmuser command removes the entire record for a user.
A basic /etc/security/environ file is shown in the following example, which has no
environment attributes defined. Therefore, the system is using default values.
# pg /etc/security/environ
default:
root:
daemon:
bin:
sys:
adm:
uucp:
guest:
13.3.2 /etc/security/lastlog
The /etc/security/lastlog file is an ASCII file that contains stanzas with the last
login attributes for users. Each stanza is identified by a user name and contains
attributes in the Attribute=Value form. Each attribute is ended by a new-line
character, and each stanza is ended by an additional new-line character. Two
stanzas for users (root & john) are shown in Figure 13-1 on page 361.
Chapter 13. User administration 361
The mkuser command creates a user stanza in the lastlog file. The attributes of
this user stanza are initially empty. The field values are set by the login
command as a result of logging in to the system. The lsuser command displays
the values of these attributes; the rmuser command removes the user stanza
from this file along with the user account.
Figure 13-1 /etc/security/lastlog stanzas
13.3.3 /etc/security/limits
The /etc/security/limits file is an ASCII file that contains stanzas that specify the
process resource limits for each user. These limits are set by individual attributes
within a stanza.
Each stanza is identified by a user name followed by a colon and contains
attributes in the Attribute=Value form. Each attribute is ended by a new-line
character, and each stanza is ended by an additional new-line character. If you
do not define an attribute for a user, the system applies default values.
The default attributes, and attributes for the user smith, are shown in Figure 13-2
on page 362.
362 IBM ^ Certification Study Guide - pSeries AIX System Administration
When you create a user with the mkuser command, the system adds a stanza for
the user to the /etc/security/limits file. Once the stanza exists, you can use the
chuser command to change the user's limits. To display the current limits for a
user, use the lsuser command. To remove users and their stanzas, use the
rmuser command.
Figure 13-2 Contents of /etc/security/limits file
13.3.4 /etc/security/user
The /etc/security/user file contains extended user attributes. This is an ASCII file
that contains attribute stanzas for users. The mkuser command creates a stanza
in this file for each new user and initializes its attributes with the default attributes
defined in the /usr/lib/security/mkuser.default file.
Each stanza in the /etc/security/user file is identified by a user name, followed by
a colon (:), and contains comma-separated attributes in the Attribute=Value form.
If an attribute is not defined for a user, either the default stanza or the default
value for the attribute is used. You can have multiple default stanzas in the
/etc/security/user file. A default stanza applies to all of the stanzas that follow, but
does not apply to the stanzas preceding it.
Each attribute is ended by a new-line character, and each stanza is ended by an
additional new-line character.
Chapter 13. User administration 363
The mkuser command creates an entry for each new user in the /etc/security/user
file and initializes its attributes with the attributes defined in the
/usr/lib/security/mkuser.default file. To change attribute values, use the chuser
command. To display the attributes and their values, use the lsuser command.
To remove a user, use the rmuser command.
Password controls
The /etc/security/user file contains many attributes that allow you to control how
users must manage their passwords. These attributes include:
histsize Defines the number of previous passwords a user cannot reuse.
The value is a decimal integer string. The default is 0.
histexpire Defines the period of time (in weeks) that a user cannot reuse a
password. The value is a decimal integer string. The default is 0,
indicating that no time limit is set.
maxexpired Defines the maximum time (in weeks) beyond the maxage value
that a user can change an expired password. After this defined
time, only an administrative user can change the password. The
value is a decimal integer string. The default is -1, indicating no
restriction is set. If the maxexpired attribute is 0, the password
expires when the maxage value is met. If the maxage attribute is
0, the maxexpired attribute is ignored.
maxage Defines the maximum age (in weeks) of a password. The
password must be changed by this time. The value is a decimal
integer string. The default is a value of 0, indicating no maximum
age.
minage Defines the minimum age (in weeks) a password must be before
it can be changed. The value is a decimal integer string. The
default is a value of 0, indicating no minimum age.
minlen Defines the minimum length of a password. The value is a
decimal integer string. The default is a value of 0, indicating no
minimum length. The maximum value allowed is 8. The value of
minlen is determined by the minalpha value added to the
minother value. If the result of this addition is greater than the
minlen attribute, the value is set to the result.
minalpha Defines the minimum number of alphabetic characters that must
be in a new password. The value is a decimal integer string. The
default is a value of 0, indicating no minimum number.
minother Defines the minimum number of non-alphabetic characters that
must be in a new password. The value is a decimal integer string.
The default is a value of 0, indicating no minimum number.
364 IBM ^ Certification Study Guide - pSeries AIX System Administration
maxrepeats Defines the maximum number of times a character can be
repeated in a new password. Since a value of 0 is meaningless,
the default value of 8 indicates that there is no maximum number.
The value is a decimal integer string.
mindiff Defines the minimum number of characters required in a new
password that were not in the old password. The value is a
decimal integer string. The default is a value of 0, indicating no
minimum number.
13.3.5 /usr/lib/security/mkuser.default
The /usr/lib/security/mkuser.default file contains the default attributes for new
users. This file is an ASCII file that contains user stanzas. These stanzas have
attribute default values for users created by the mkuser command. Each attribute
has the Attribute=Value form. If an attribute has a value of $USER, the mkuser
command substitutes the name of the user. The end of each attribute pair and
stanza is marked by a new-line character.
There are two stanzas, user and admin, that can contain all defined attributes
except the ID and admin attributes. The mkuser command generates a unique ID
attribute. The admin attribute depends on whether the -a flag is used with the
mkuser command. The following example shows a typical stanza in
/usr/lib/security/mkuser.default.
# pg /usr/lib/security/mkuser.default
user:
pgrp = staff
groups = staff
shell = /usr/bin/ksh
home = /home/$USER
admin:
pgrp = system
groups = system
shell = /usr/bin/ksh
home = /home/$USER
13.3.6 /usr/lib/security/mkuser.sys
The /usr/lib/security/mkuser.sys file is an ASCII file of runable commands that is
called by the mkuser command. The /usr/lib/security/mkuser.sys file creates the
new user’s home directory with the correct owner and primary group, and creates
the appropriate profile for the user's shell. This file can be customized to tailor the
creation of new users.
Chapter 13. User administration 365
13.3.7 /etc/passwd
The /etc/passwd file contains basic user attributes. This is an ASCII file that
contains an entry for each user. Each entry defines the basic attributes applied to
a user.
When you use the mkuser command to add a user to your system, the command
updates the /etc/passwd file.
An entry in the /etc/passwd file has the following form with all attributes
separated by a colon(:).
Name:Password: UserID:PrincipleGroup:Gecos: HomeDirectory:Shell
Password attributes can contain an asterisk (*) indicating an incorrect password
or an exclamation point (!) indicating that the password is in the
/etc/security/passwd file. Under normal conditions, the field contains an
exclamation point (!). If the field has an asterisk (*) and a password is required for
user authentication, the user cannot log in.
The shell attribute specifies the initial program or shell (login shell) that is started
after a user invokes the login command or su command. The Korn shell is the
standard operating system login shell and is backwardly compatible with the
Bourne shell. If a user does not have a defined shell, /usr/bin/sh, the system
default shell (Bourne shell) is used. The Bourne shell is a subset of the Korn
shell.
The mkuser command adds new entries to the /etc/passwd file and fills in the
attribute values as defined in the /usr/lib/security/mkuser.default file. The
Password attribute is always initialized to an asterisk (*), which is an invalid
password. You can set the password with the passwd or pwdadm commands. When
the password is changed, an exclamation point (!) is added to the /etc/passwd file
indicating that the encrypted password is in the /etc/security/passwd file.
Use the chuser command to change all user attributes except Password. The
chfn command and the chsh command change the Gecos attribute and Shell
attribute, respectively. To display all the attributes in this file, use the lsuser
command. To remove a user and all the user's attributes, use the rmuser
command.
366 IBM ^ Certification Study Guide - pSeries AIX System Administration
The contents of /etc/passwd file in Figure 13-3 shows that the Password
attributes for two users (john and bob) are ! and *, respectively, which implies that
user bob cannot login, as it has an invalid password.
Figure 13-3 Contents of /etc/passwd file
13.3.8 /etc/security/passwd
The /etc/security/passwd file is an ASCII file that contains stanzas with password
information. Each stanza is identified by a user name followed by a colon (:) and
contains attributes in the form Attribute=Value. Each attribute is ended with a new
line character, and each stanza is ended with an additional new line character.
Chapter 13. User administration 367
Although each user name must be in the /etc/passwd file, it is not necessary to
have each user name listed in the /etc/security/passwd file. A typical file would
have contents is similar to that shown in Figure 13-4.
Figure 13-4 Contents of /etc/security/passwd file
13.3.9 /etc/security/login.cfg
The /etc/security/login.cfg file (Figure 13-5 on page 368) is an ASCII file that
contains stanzas of configuration information for login and user authentication.
Each stanza has a name, followed by a : (colon). Attributes are in the form
Attribute=Value. Each attribute ends with a new-line character, and each stanza
ends with an additional new-line character. There are three types of stanzas.
port stanza Defines the login characteristics of ports.
authentication stanza Defines the authentication methods for users.
user configuration stanza Defines programs that change user attributes (usw).
368 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 13-5 Contents of /etc/security/login.cfg file
13.3.10 /etc/utmp, /var/adm/wtmp, /etc/security/failedlogin
The utmp file, the wtmp file, and the failedlogin file contain records with user and
accounting information. When a user successfully logs in, the login program
writes entries in two files.
The /etc/utmp file, which contains a record of users logged into the system.
The command who -a processes the /etc/utmp file, and if this file is corrupted
or missing, no output is generated from the who command.
The /var/adm/wtmp file (if it exists), which contains connect-time accounting
records.
On an invalid login attempt, due to an incorrect login name or password, the login
program makes an entry in the /etc/security/failedlogin file, which contains a
record of unsuccessful login attempts.
13.3.11 /etc/motd
The message of the day is displayed every time a user logs in to the system. It is
a convenient way to communicate information to all users, such as installed
software version numbers or current system news. The message of the day is
contained in the /etc/motd file. To change the message of the day, simply edit that
file.
Chapter 13. User administration 369
A typical /etc/motd file would look like Figure 13-6.
Figure 13-6 Sample /etc/motd file
13.3.12 /etc/environment
The /etc/environment file contains variables specifying the basic environment for
all processes. When a new process begins, the exec subroutine makes an array
of strings available that have the form Name=Value. This array of strings is called
the environment. Each name defined by one of the strings is called an
environment variable or shell variable. Environment variables are examined
when a command starts running.
The /etc/environment file is
not a shell script. It should only contain data in
Name=Value format, and should not contain shell commands. Trying to run
commands from this file may cause failure of the initialization process.
When you log in, the system sets environment variables from the environment
file before reading your login profile, .profile. Following are a few variables that
make up part of the basic environment.
HOME The full path name of the user login or HOME directory. The login
program sets this to the directory specified in the /etc/passwd file.
LANG The locale name currently in effect. The LANG variable is set in the
/etc/environment file at installation time.
NLSPATH The full path name for message catalogs.
370 IBM ^ Certification Study Guide - pSeries AIX System Administration
PATH The sequence of directories that commands, such as sh, time,
nice, and nohup search when looking for a command whose path
name is incomplete. The directory names are separated by colons.
LPDEST The printer to use when a print-related command does not specify
a destination printer.
TERM The terminal type.
EDITOR The default editor to be used by various commands that perform
editing functions, such as crontab.
TZ The time zone information. The TZ environment variable is set by
the /etc/environment file.
13.3.13 /etc/profile and $HOME/.profile
The /etc/profile file contains further environment variables, as well as any
commands to run, that apply to all users. Use the /etc/profile file to control
variables such as:
Export variables
File creation mask (umask)
Terminal types
Mail messages to indicate when new mail has arrived
Commands to be included in /etc/profile should be appropriate for
all users of the
system. An example of a command that you may want all users to run when they
log in is the news command.
The $HOME/.profile file enables you to customize your individual working
environment. The .profile file also overrides commands and variables set in the
/etc/profile file. Use the .profile file to control personal settings such as:
Shells to open
Default editor
Default printer
Prompt appearance
Keyboard sound
Attention: Changing the time zone only affects processes that begin after the
change is made. The init process only reads /etc/environment at startup,
therefore init and its child processes will not be aware of a change to TZ until
the system is rebooted.
Chapter 13. User administration 371
13.4 User administration tasks
User administration creates users, defines or changes their attributes, and
defines the security environment for the users. These topics are discussed in the
following sections.
13.4.1 Adding a new user account
The mkuser command creates a new user account. The Name parameter must
be a unique 8-byte or less string. By default, the mkuser command creates a
standard user account. To create an administrative user account, specify the -a
flag.
The mkuser command does not create password information for a user, therefore,
the new accounts are disabled until the passwd command is used to add
authentication information to the /etc/security/passwd file. The mkuser command
only initializes the Password attribute of /etc/passwd file with an * (asterisk).
To create the smith account with smith as an administrator, enter:
mkuser -a smith
You must be the root user to create smith as an administrative user.
To create the smith user account and set the su attribute to a value of false
enter:
mkuser su=false smith
To create a user account, smith, with the default values in the
/usr/lib/security/mkuser.default file, enter:
mkuser smith
Alternatively, you can use SMIT:
a. Run smitty mkuser to access the menu as shown in Figure 13-7 on
page 372.
b. Type smith for the field User NAME.
c. Press the Enter key to create the user.
d. When SMIT returns an OK prompt, Press the F10 key to return to the
command prompt
372 IBM ^ Certification Study Guide - pSeries AIX System Administration
.
Figure 13-7 Adding a user
13.4.2 Creating or changing user password
The passwd command will create an encrypted passwd entry in
/etc/security/passwd and change the Password attribute of /etc/passwd from * to
! (exclamation).
To change your full name in the /etc/passwd file, enter:
passwd -f smith
The passwd command displays the name stored for your user ID. For
example, for login name smith, the passwd command could display the
message as shown in the following example.
# passwd -f smith
smith's current gecos:
"Mr J.Smith"
Change (yes) or (no)? > n
Gecos information not changed.
If you enter a Y for yes, the passwd command prompts you for the new name.
The passwd command records the name you enter in the /etc/passwd file.
To change your password, enter:
passwd
Chapter 13. User administration 373
The passwd command prompts you for your old password, if it exists and you
are not the root user. After you enter the old password, the command prompts
you twice for the new password.
Alternatively, you can use SMIT:
a. Running smitty passwd will prompt you to a menu as shown in
Figure 13-8.
b. Type smith for the field User NAME.
c. Press Enter, and you will be prompted to enter the new password (twice)
as shown in Figure 13-9 on page 374.
d. Enter the new password and press the Enter key.
e. When SMIT returns an OK prompt, press the F10 key to return to the
command prompt.
Figure 13-8 Changing a user password
374 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 13-9 Entering a user password
13.4.3 Changing user attributes
The chuser command changes attributes for the user identified by the Name
parameter. The user name must already exist as an alphanumeric string of eight
bytes or less.
Only the root user can use the chuser command to perform the following tasks:
Make a user an administrative user by setting the admin attribute to true.
Change any attributes of an administrative user.
Add a user to an administrative group.
The following examples show the use of the chuser command with various flags.
To enable user smith to access this system remotely, enter:
chuser rlogin=true smith
Note: Do not use the chuser command if you have a Network Information
Service (NIS) database installed on your system.
Chapter 13. User administration 375
To change the date that the smith user account will expire to 8 a.m., 1
December, 1998, enter:
chuser expires=1201080098 smith
To add smith to the group programers, enter:
chuser groups=programers smith
Alternatively, you can go through the SMIT hierarchy by:
a. Running smitty chuser will prompt you to a menu as shown in
Figure 13-10 on page 375.
b. Type smith for the field User NAME.
c. Use the Arrows key to highlight the Primary GROUP field and type
programmer in it.
d. Press Enter.
e. When SMIT returns an OK prompt, press the F10 key to return to the
command prompt.
Figure 13-10 Changing user characteristics
376 IBM ^ Certification Study Guide - pSeries AIX System Administration
13.4.4 Displaying user attributes
The lsuser command displays the user account attributes. You can use this
command to list all attributes of all the users or all the attributes of specific users
except their passwords. Since there is no default parameter, you must enter the
ALL keywords to see the attributes of all the users. By default, the lsuser
command displays all user attributes. To view selected attributes, use the -a List
flag. If one or more attributes cannot be read, the lsuser command lists as much
information as possible.
By default, the lsuser command lists each user's attributes on one line. It
displays attribute information as Attribute=Value definitions each separated by a
blank space. To list the user attributes in stanza format, use the -f flag. To list the
information as colon-separated records, use the -c flag.
The following examples shows the use of the lsuser command with various
flags.
To display the user ID and group-related information for the root account in
stanza form, enter:
# lsuser -f -a id pgrp home root
root:
id=0
pgrp=system
home=/
To display the user ID, groups, and home directory of user smith in colon
format, enter:
lsuser -c -a id home groups smith
To display all the attributes of user smith in the default format, enter:
lsuser smith
All the attribute information appears with each attribute separated by a blank
space.
To display all the attributes of all the users, enter:
lsuser ALL
All the attribute information appears with each attribute separated by a blank
space.
Note: If you have a Network Information Service (NIS) database installed
on your system, some user information may not appear when you use the
lsuser command.
Chapter 13. User administration 377
Alternatively, you can use SMIT:
a. Run smitty lsuser, which will prompt you to a menu as shown in
Figure 13-11 on page 377.
b. Type smith for the field User NAME and press Enter. This will display a
screen as shown in Figure 13-12 on page 378.
c. When SMIT returns an OK prompt, press the F10 key to return to the
command prompt.
Figure 13-11 smitty users command
378 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 13-12 Listing user characteristics
13.4.5 Removing a user account
The rmuser command removes the user account identified by the Name
parameter. This command removes a user's attributes without removing the
user's home directory and files. The user name must already exist as a string of
eight bytes or less. If the -p flag is specified, the rmuser command also removes
passwords and other user authentication information from the
/etc/security/passwd file.
Only the root user can remove administrative users.
The following example shows the use of the rmuser command to remove a
user account smith and its attributes from the local system:
rmuser smith
To remove the user smith account and all its attributes, including passwords
and other user authentication information in the /etc/security/passwd file, use
the following command:
rmuser -p smith
Alternatively, you can go through the SMIT hierarchy by:
a. Running smitty rmuser will prompt you to a menu as shown in
Figure 13-13 on page 379.
Chapter 13. User administration 379
b. Type smith for the field User NAME.
c. Press the Enter key.
d. When SMIT returns an OK prompt, Press the F10 key to return to the
command prompt.
Figure 13-13 Removing a user
13.4.6 Changing security attributes of user
The chsec command changes the attributes stored in the security configuration
stanza files. The following security configuration stanza files have attributes that
you can specify with the Attribute = Value parameter.
/etc/security/environ
/etc/security/group
/etc/security/lastlog
/etc/security/limits
/etc/security/login.cfg
/usr/lib/security/mkuser.default
/etc/security/passwd
/etc/security/portlog
/etc/security/user
380 IBM ^ Certification Study Guide - pSeries AIX System Administration
When modifying attributes in the /etc/security/environ, /etc/security/lastlog,
/etc/security/limits, /etc/security/passwd, and /etc/security/user files, the stanza
name specified by the Stanza parameter must either be a valid user name or
default.
When modifying attributes in the /etc/security/group file, the stanza name
specified by the Stanza parameter must either be a valid group name or default.
When modifying attributes in the /usr/lib/security/mkuser.default file, the Stanza
parameter must be either admin or user.
When modifying attributes in the /etc/security/portlog file, the Stanza parameter
must be a valid port name. When modifying attributes in the
/etc/security/login.cfg file, the Stanza parameter must either be a valid port name,
a method name, or the usw attribute.
When modifying attributes in the /etc/security/login.cfg or /etc/security/portlog
files in a stanza that does not already exist, the stanza is automatically created
by the chsec command.
The following examples show the usage of chsec command to change security
stanzas in various files.
To change the /dev/tty0 port to automatically lock if five unsuccessful login
attempts occur within 60 seconds, enter:
chsec -f /etc/security/login.cfg -s /dev/tty0 -a logindisable=5 -a
logininterval=60
To unlock the /dev/tty0 port after it has been locked by the system, enter:
chsec -f /etc/security/portlog -s /dev/tty0 -a locktime=0
To allow logins from 8:00 a.m. until 5:00 p.m. for all users, enter:
chsec -f /etc/security/user -s default -a logintimes=:0800-1700
To change the CPU time limit of user smith to one hour (3600 seconds), enter:
chsec -f /etc/security/limits -s smith -a cpu=3600
Note: You cannot modify the password attribute of the /etc/security/passwd
file using the chsec command. Instead, use the passwd command.
Chapter 13. User administration 381
13.4.7 Displaying currently logged users
The who command displays information about all users currently on the local
system. The following information is displayed: Login name, tty, and the date and
time of login. Entering who am i or who am I displays your login name, tty, and
the date and time you logged in. If the user is logged in from a remote machine,
then the host name of that machine is displayed as well. The who command can
also display the elapsed time since line activity occurred, the process ID of the
command interpreter (shell), logins, logoffs, restarts, and changes to the system
clock, as well as other processes generated by the initialization process.
The following examples show the usage of the who command with various flags.
The following example shows the command to display information about all
the users who are logged on to the system:
# who
root pts/0 Nov 17 10:20 (sv1166a.itsc.aus)
root pts/2 Nov 23 10:45 (sv1121c.itsc.aus)
root pts/3 Nov 23 10:48 (sv1121c)
The following example shows the command to display your user name:
# who am I
root pts/3 Nov 23 10:48 (sv1121c)
The following shows how to display the run-level of the local system:
# who -r
. run-level 2 Nov 17 10:19 2 0 S
To display any active process that was spawned by init, run the following
command:
# who -p
rc . Nov 17 10:19 4:12 2896 id=rc
fbcheck . Nov 17 10:19 4:12 2898 id=fbcheck
srcmstr . Nov 17 10:19 4:12 2900 id=srcmstr
rctcpip . Nov 17 10:19 4:12 4648 id=rctcpip
rcnfs . Nov 17 10:19 4:12 4650 id=rcnfs
cron . Nov 17 10:19 4:12 4652 id=cron
piobe . Nov 17 10:19 4:12 4984 id=piobe
qdaemon . Nov 17 10:19 4:12 4986 id=qdaemon
writesrv . Nov 17 10:19 4:12 4988 id=writesr
uprintfd . Nov 17 10:19 4:12 4990 id=uprintf
pmd . Nov 17 10:19 4:12 8772 id=pmd
dt . Nov 17 10:19 4:12 9034 id=dt
Note: The /etc/utmp file contains a record of users logged into the system.
The command who -a processes the /etc/utmp file, and if this file is
corrupted or missing, no output is generated from the who command.
382 IBM ^ Certification Study Guide - pSeries AIX System Administration
In the event that the /etc/utmp file becomes corrupt or lost, you can use the ps
command to list processes and their associated users.
13.4.8 Preventing user logins
If the /etc/nologin file exists, the system accepts the user’s name and password,
prevents the user from logging in and displays the contents of the /etc/nologin
file. The system does allow the root user to log in if this file exists. The
/etc/nologin file is removed when you reboot the system. You can also allow
users to log in again by deleting the file.
13.4.9 Changing a user’s login shell
The chsh command changes a user's login shell attribute. The shell attribute
defines the initial program that runs after a user logs in to the system. This
attribute is specified in the /etc/passwd file. By default, the chsh command
changes the login shell for the user who gives the command.
The chsh command is interactive. When you run the chsh command, the system
displays a list of the available shells and the current value of the shell attribute, as
shown in Figure 13-14. In addition to the default shells (/usr/bin/ksh, /usr/bin/sh,
/usr/bin/bsh, /usr/bin/csh) your system manager may have defined more. Then,
the system prompts you to change the shell. You must enter the full path name of
an available shell.
If you have execute permission for the chuser command, you can change the
login shell for another user.
Chapter 13. User administration 383
Figure 13-14 chsh command
13.4.10 Changing the shell prompt
The shell uses the following three prompt variables.
PS1 Prompt used as the normal system prompt.
PS2 Prompt used when the shell expects more input.
PS3 Prompt used when you have root authority.
You can change any of your prompt characters by changing the value of its shell
variable. The changes to your prompts last until you log off. To make your
changes permanent, place them in your .env file.
The following command shows how to display the current value of the PS1
variable.
# echo "prompt is $PS1":
prompt is $
The following example shows the command to change the prompt to Ready>:
export PS1="Ready> "
The following example shows the command to change the continuation prompt to
Enter more->:
384 IBM ^ Certification Study Guide - pSeries AIX System Administration
export PS2="Enter more->"
The following example shows the command to change the root prompt to Root->:
export PS3="Root-> "
13.4.11 Starting AIX Common Desktop Environment
If the AIX Common Desktop Environment (CDE) is not set up to start
automatically on a locally attached graphics display, you can use the following
command to start the desktop from an AIX command line.
xinit /usr/dt/bin/Xsession
Using the xinit command starts the desktop without bringing up the whole
desktop environment. You will bypass the login window when you start the
desktop, and when you exit, you will return to a command line rather than an AIX
CDE login window. You will, however, use the same desktop applications you
would use had you started the desktop from the welcome window.
You can set up the system so that the AIX CDE comes up automatically when
you start the system, or you can start AIX CDE manually. You must log in as root
to perform each of these tasks.
Enabling and disabling desktop autostart
To enable the desktop autostart, use smitty dtconfig or dtconfig -e.
To disable the desktop autostart, use smitty dtconfig or dtconfig -d.
After enabling or disabling desktop autostart, reboot the system.
Starting AIX Common Desktop Environment manually.
Use the following command to start the AIX CDE at the command line.
/usr/dt/bin/dtlogin -daemon
A Desktop Login window will display. When you log in, you will start a desktop
session.
Stopping AIX Common Desktop Environment manually.
When you manually stop the login manager, all X servers and desktop sessions
that the login manager started are stopped.
Note: If the desktop autostart is enabled on a system with no graphics
capability, it may make using the serial console difficult. To prevent problems,
disable the desktop autostart and reboot.
Chapter 13. User administration 385
1. Open a terminal emulator window and log in as root.
2. Obtain the process ID of the Login Manager by entering the following:
cat /var/dt/Xpid
3. Stop the Login Manager by entering:
kill -term process_id
13.5 Common login errors
The following section summarizes a few of the Error Messages for Component ID
3004 (login errors) and their possible causes. Refer to the AIX product
documentation for more information.
3004-004 You must "exec" login from the lowest login shell. You
attempted to log off the system while processes are still running
in another shell.
3004-007 You entered an invalid login name or password. You tried to
log in to a system that does not recognize your login or
password.
3004-008 Failed setting credentials. Login failed.
3004-009 Failed running login shell. You tried to log in to a system that
has a damaged login shell. The login shell does not exist.
3004-030 You logged in using all uppercase characters. You
attempted to log in with Caps Lock on.
3004-031 Password read timed out--possible noise on port. You
logged in but did not enter your password within a specified
amount of time. Your password was not validated within a
specified amount of time due to a failed network connection.
3004-302 Your account has expired. Please see the system
administrator. Your password has expired.
3004-312 All available login sessions are in use. You tried to log in to
a system that had all present sessions in use.
3004-687 User does not exist. You specified an invalid user name with
the lsuser, chuser, rmuser, or passwd command.
386 IBM ^ Certification Study Guide - pSeries AIX System Administration
13.5.1 AIX Common Desktop Environment and full file systems
Users will not be able to log in using the AIX CDE when the /home file system is
full. If /home is full, the AIX CDE welcome window will accept the user’s name
and password, the display will then go blank and appear to hang, then will return
to the AIX CDE welcome window. To log in and investigate, press the Options
button on the AIX CDE welcome window and select Command Line Login, or log
in from a non graphics display.
13.6 Quiz
The following are questions created by the authors to further test your
understanding of the topics.
1. A user is able to get a login prompt for the server but gets a failed login error
message when trying to login with an ID. Which of the following is the most
likely cause of this problem?
A. The hard drive is bad.
B. The /home file system is full.
C. The server is low on paging space.
D. The user has entered an invalid ID or password.
2. Which of the following files contains UID, home directory, and shell
information?
A. /etc/passwd
B. /etc/security/user
C. /etc/security/environ
D. /etc/security/passwd
Chapter 13. User administration 387
3. A customer has cloned a machine using mksysb. The source machine
contained a graphics adaptor and display and was running Xwindows. The
target machine has an IBM 3151 terminal and no graphics capability. The
customer states that they are seeing the following message repeatedly scroll
across the login screen.
*******************************************************
* Starting Desktop Login on display :0÷
*
* Wait for the Desktop Login screen before logging in.
*
*******************************************************
To prevent this message from appearing, which of the following actions
should be performed?
A. Run the cdecfg -disable command.
B. Run the startx -no command and reboot.
C. Run the dtconfig -d command and reboot.
D. Remove the X=start line from the /etc/security/login.cfg file and reboot.
4. After completing the installation of the Base Operating System on one of the
servers, the system administrator would like for all users who telnet into this
machine to see a specific message each time they successfully log in. Which
file should be edited to provide this message?
A. /etc/motd
B. /etc/profile
C. /etc/environment
D. /etc/security/login.cfg
5. A marketing manager would like her shell prompt to reflect the directory she is
in so that if she needs to remove a file, she will be sure to be in the proper
directory. Which of the following environment variables can be set to
accomplish this?
A. PS1
B. PATH
C. DISPLAY
D. LOCPATH
388 IBM ^ Certification Study Guide - pSeries AIX System Administration
13.6.1 Answers
The following answers are for the quiz questions.
1. D
2. A
3. C
4. A
5. A
13.7 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Add a new user account (james) and try to log in to the new account. Can you
log in without creating a password for this account?
2. Create a password for a newly created user account (james).
3. You want all the users to get the following message when they log in:
***************************************************************************
Please assemble in the meeting room at 13:00 hrs on Nov.20,2001
****************************************************************************
Which file needs to be edited to contain this message so that the message is
displayed when a user logs in?
4. Move the file /etc/utmp to /etc/wtmp.org. Run the who command. What is the
output?
5. Change the password of a user account who does not remember his old
password.
6. How can you disable the desktop autostart?
7. Display the attributes of the user account.
8. Permanently change your shell prompt to display the current directory.
© Copyright IBM Corp. 2001 389
Chapter 14. Printing
This chapter discusses the AIX print subsystem and does not cover the optional
SRV4 print subsystem, which is available in AIX 5L Version 5.1.
The following defines terms commonly used when discussing UNIX printing.
Print job
A print job is a unit of work to be run on a printer. A print job can consist of
printing one or more files depending on how the print job is requested. The
system assigns a unique job number to each job it runs.
Queue
The queue is where you direct a print job. It is a stanza in the /etc/qconfig file
whose name is the name of the queue and points to the associated queue
device.
Queue device
The queue device is the stanza in the /etc/qconfig file that normally follows the
local queue stanza. It specifies the /dev file (printer device) that should be
used.
14
Note: There can be more than one queue device associated with a
single queue.
390 IBM ^ Certification Study Guide - pSeries AIX System Administration
qdaemon
The qdaemon is a process that runs in the background and controls the
queues. It is generally started during IPL with the startsrc command. See
Section 9.1, “Starting the SRC” on page 246 for more information.
Print spooler
A spooler is not specifically a print job spooler. Instead, it provides a generic
spooling function that can be used for queuing various types of jobs including
print jobs queued to a printer.
The spooler does not normally know what type of job it is queuing. When the
system administrator defines a spooler queue, the purpose of the queue is
defined by the spooler backend program that is specified for the queue. For
example, if the spooler backend program is the piobe command (the printer
I/O backend), the queue is a print queue. Likewise, if the spooler backend
program is a compiler, the queue is for compile jobs. When the spooler's
qdaemon command selects a job from a spooler queue, it runs the job by
invoking the backend program specified by the system administrator when the
queue was defined.
The main spooler command is the enq command. Although you can invoke
this command directly to queue a print job, three front-end commands are
defined for submitting a print job: The lp, lpr, and qprt commands. A print
request issued by one of these commands is first passed to the enq
command, which then places the information about the file in the queue for
the qdaemon to process.
Real printer
A real printer is the printer hardware attached to a serial or parallel port at a
unique hardware device address. The printer device driver in the kernel
communicates with the printer hardware and provides an interface between
the printer hardware and a virtual printer, but it is not aware of the concept of
virtual printers. Real printers sometimes run out of paper.
Local and remote printers
When you attach a printer to a node or host, the printer is referred to as a
local printer. A remote print system allows nodes that are not directly linked to
a printer to have printer access.
To use remote printing facilities, the individual nodes must be connected to a
network using Transmission Control Protocol/Internet Protocol (TCP/IP) and
must support the required TCP/IP applications.
Chapter 14. Printing 391
Printer backend
The printer backend is a collection of programs called by the spooler's
qdaemon command to manage a print job that is queued for printing. The
printer backend performs the following functions:
– Receives a list of one or more files to be printed from the qdaemon
command.
– Uses printer and formatting attribute values from the database; overridden
by flags entered on the command line.
– Initializes the printer before printing a file.
– Runs filters as necessary to convert the print data stream to a format
supported by the printer.
– Provides filters, for simple formatting of ASCII documents.
– Provides support for printing national language characters.
– Passes the filtered print data stream to the printer device driver.
– Generates header and trailer pages.
– Generates multiple copies.
– Reports paper out, intervention required, and printer error conditions.
– Reports problems detected by the filters.
– Cleans up after a print job is cancelled.
– Provides a print environment that a system administrator can customize to
address specific printing needs.
Table 14-1 provides a list of commands that can perform the same function.
Table 14-1 Print commands and their equivalents
14.1 Creating a new print queue
The best way for you to create a new print queue is by using the SMIT interface.
Here are the steps you need to follow.
Submit print jobs Status print jobs Cancel print jobs
enq enq -A enq -x
qprt qchk qcan
lp lpstat lprm
lpr lpq
394 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 14-3 shows the Print Spooling menu, in which an Add a Print Queue sub
menu will appear. Select what the printer is connected to, in this case, local, and
press Enter.
Figure 14-3 Add a Print Queue menu screen - print queue selection
Once you selected where the printer is connected to, select what kind of printer it
is and press Enter. In Figure 14-4 on page 395, Other (select this if your printer
type is not listed above) has been selected.
396 IBM ^ Certification Study Guide - pSeries AIX System Administration
You now need to select the Printer Interface. As shown in Figure 14-6, select
parallel as your choice and press Enter.
Figure 14-6 Print Spooling menu - Printer Interface selection
Once your Printer Interface has been selected, you need to select the Parent
Adapter (in Figure 14-7 on page 397, select ppa0 Available 01-D0 Standard I/O
Parallel Port Adapter as your choice) and press Enter.
Chapter 14. Printing 397
Figure 14-7 Print Spooling menu - Parent Adapter selection
Once this process is complete, you will Add a Print Queue, as shown in
Figure 14-8 on page 398. This is where you select what you want to call your
printer. In this case, the printer is called lpforu. You can change any of the
characteristics of the printer if you need; however, this is normally not needed.
398 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 14-8 Add a Print Queue menu - printer characteristics
Once you have entered your characteristics, the COMMAND STATUS menu will
appear informing you of the success of your action, as shown in Figure 14-9.
Figure 14-9 New print queue Command Status
Chapter 14. Printing 399
Once complete, press F10 to exit.
You have now installed the print queue lpforu on the printer lp0.
14.2 The print configuration file
The file that holds the configuration for the printers that exist on the system is the
/etc/qconfig file. It is the most important file in the spooler domain for these
reasons:
It contains the definition of every queue known to the spooler.
A system administrator can read this file and discern the function of each
queue.
Although it is not recommended, this file can be edited to modify spooler
queues without halting the spooler.
The /etc/qconfig file describes all of the queues defined in the AIX operating
system. A queue is a named, ordered list of requests for a specific device. A
device is something (either hardware or software) that can handle those requests
one at a time. The queue provides serial access to the device. Each queue must
be serviced by at least one device; often it can be handled by more than one
device.
The following is an example of the contents of the /etc/qconfig file:
* @(#)33 1.6 src/bos/usr/bin/que/qconfig.sh, cmdque, bos430, 9737A_430
2/4/94 10:45:05
* IBM_PROLOG_BEGIN_TAG
..........
* IBM_PROLOG_END_TAG
*
* COMPONENT_NAME: cmdque configuration file for spooling
..........
* PRINTER QUEUEING SYSTEM CONFIGURATION
*
* This configuration file contains valid configurations for remote
* print queue rp0, local print queue lp0 and batch queue bsh.
* They may be deleted or changed as necessary.
*
* EXAMPLE of remote print queue configuration
* rp0:
* host = hostname
* s_statfilter = /usr/lib/lpd/aixshort
* l_statfilter = /usr/lib/lpd/aixlong
* rq = queuename
* device = drp0
400 IBM ^ Certification Study Guide - pSeries AIX System Administration
*
* drp0:
* backend = /usr/lib/lpd/rembak
*
* EXAMPLE of local print queue configuration
*lp0:
* discipline = fcfs
* up = TRUE
* device = dlp0
*
*dlp0:
* backend = /usr/lib/lpd/piobe
* file = FALSE
* access = write
* feed = never
* header = never
* trailer = never
*
* BATCH queue for running shell scripts
*
*bsh:
* device = bshdev
* discipline = fcfs
*bshdev:
* backend = /usr/bin/bsh
lpforu:
device = lp0
lp0:
file = /dev/lp0
header = never
trailer = never
access = both
backend = /usr/lib/lpd/piobe
The file /etc/qconfig is composed of text blocks referred to as stanzas. Each
queue is represented by a pair of stanzas. The first stanza in a pair is referred to
as the queue stanza; the second stanza in a pair is referred to as the device
stanza. Stanzas are composed of parameters and parameter values that
describe the queue's properties and functions.
Chapter 14. Printing 401
14.3 Controlling the print queue
This section examines some of the commands that you would use with the print
queue.
The lpstat command displays information about the current status of the line
printer.
The lpstat command syntax is as follows:
lpstat [ -aList ] [ -cList ] [ -d ] [ -oList ] [ -pList ] [ -r ] [ -s ]
[ -t ] [ -uList ] [ -vList ] [ -W ]
An example of the lpstat command, without any flags, is as follows:
# lpstat
Queue Dev Status Job Files User PP% Blks Cp Rnk
------ ---- ------- --- ---------------- ------------ --- ---- -- ---
lpforu lp0 READY
The qchk command displays the current status information regarding
specified print jobs, print queues, or users.
The qchk command syntax is as follows:
qchk [ -A ] [ -L | -W ] [ -P Printer ] [ -# JobNumber ] [ -q ]
[ -u UserName ] [ -w Delay ]
An example of the qchk command, without any flags, is as follows:
# qchk
Queue Dev Status Job Files User PP% Blks Cp Rnk
------ ---- ------- --- ---------------- ------------ --- ---- -- ---
lpforu lp0 READY
The lpq command reports the status of the specified job or all jobs associated
with the specified UserName and JobNumber variables.
The lpq command syntax is as follows:
lpq [ + [ Number ] ] [ -l | -W ] [-P Printer ] [JobNumber] [UserName]
The following is an example of the lpq command, without any flags:
# lpq
Queue Dev Status Job Files User PP% Blks Cp Rnk
------ ---- ------- --- ---------------- ------------ --- ---- -- ---
lpforu lp0 READY
The lpr command uses a spooling daemon to print the named File parameter
when facilities become available.
The lpr command syntax is as follows:
lpr [ -f ] [ -g ] [ -h ] [ -j ] [ -l ] [ -m ] [ -n ] [ -p ] [ -r ] [ -s ]
[ -P Printer ] [ -# NumberCopies ] [ -C Class ] [ -J Job ] [ -T Title ]
[ -i [ NumberColumns ] ] [ -w Width ] [ File ... ]
402 IBM ^ Certification Study Guide - pSeries AIX System Administration
The following is an example of using the lpr command to print the file
/etc/passwd.
# lpr /etc/passwd
# lpstat
Queue Dev Status Job Files User PP % Blks Cp Rnk
------ ---- -------- --- ---------------- -------- ---- -- ---- -- ---
lpforu lp0 RUNNING 3 /etc/passwd root 1 100 1 1 1
14.3.1 Editing /etc/qconfig
The /etc/qconfig file can be modified with your favorite text editor. This may be
required if you are unable to remove a printer definition by any other means.
There are unenforced rules concerning when you can and cannot edit
/etc/qconfig without halting or corrupting the operation of the spooler. This is the
topic of discussion in the next section.
14.3.2 Modifying /etc/qconfig while jobs are processing
The /etc/qconfig file should never be edited when jobs are processing. This is
especially true when your system has a large number (greater than 25) of
printers that are generally busy. When the qdaemon receives notification from
enq that a new Job Description File (JDF) exists, the qdaemon examines the
dates on both /etc/qconfig and /etc/qconfig.bin, the binary version of /etc/qconfig.
If /etc/qconfig is younger than /etc/qconfig.bin, the qdaemon does not accept any
new jobs, including the one that caused it to examine the aforementioned files,
until all currently running jobs have finished processing. When the jobs have
finished processing, the qdaemon creates a new version of /etc/qconfig.bin.
If you cause the qdaemon to go into this state while jobs are processing, it is
possible for the spooler to hang.
14.4 Stopping the print queue
In the following scenario, you have a job printing on a print queue, but you need
to stop the queue so that you can put more paper in the printer.
Check the print queue using the lpstat command, as shown in the following
example. The reason for the -v flag is so that you do not get a listing of all the
printers. See Table 14-4 on page 405 for a list of lpstat command flags.
# lpstat -vlpforu
Queue Dev Status Job Files User PP % Blks Cp Rnk
------ ---- -------- --- ---------------- -------- ---- -- ---- -- ---
lpforu lp0 RUNNING 3 /etc/passwd root 1 100 1 1 1
Chapter 14. Printing 403
Disable the print queue using the enq command, as shown in the following
example. See Table 14-2 for a list of enq command flags.
# enq -D -P 'lpforu:lp0'
Check the printer queue using the qchk command, as shown in the following
example. See Table 14-3 for some qchk command flags.
# qchk -P lpforu
Queue Dev Status Job Files User PP % Blks Cp Rnk
------ ---- -------- --- ---------------- -------- ---- -- ---- -- ---
lpforu lp0 DOWN 3 /etc/passwd root 1 100 1 1 1
Table 14-2 Flags for the enq command
Table 14-3 Flags for the qchk command
Flag Description
-D Device DOWN. Turns off the device associated with the queue. The
qdaemon process no longer send jobs to the device.
-U Brings UP the device associated with a queue. The qdaemon process
sends jobs to it again.
-P Queue Specifies the queue to which the job is sent. A particular device on a
queue can be specified by typing -P Queue:Device.
Flag Description
-# JobNumber Requests the status of the job number specified by the JobNumber
variable. The qchk command looks for JobNumber on the default
queue when the -#JobNumber flag is used alone. To search for
JobNumber on all queues, the -# flag must be used with the -A flag.
The -# flag may also be used in conjunction with the -P Queue flag.
-A Requests the status of all queues.
-P Printer Requests the status of the printer specified by the Printer variable.
-u UserName Requests the status of all print jobs sent by the user specified by the
UserName variable.
-w Delay Updates requested status information at intervals, in seconds, as
specified by the Delay variable until all print jobs are finished.
404 IBM ^ Certification Study Guide - pSeries AIX System Administration
14.5 Starting the print queue
You have replaced the paper, and you now want to restart the print queue so that
it will finish your print job. Here is how you would do this:
# lpstat -vlpforu
Queue Dev Status Job Files User PP % Blks Cp Rnk
------ ---- -------- --- ---------------- -------- ---- -- ---- -- ---
lpforu lp0 DOWN 3 /etc/passwd root 1 100 1 1 1
# enq -U -P 'lpforu:lp0'
# qchk -P lpforu
Queue Dev Status Job Files User PP % Blks Cp Rnk
------ ---- -------- --- ---------------- -------- ---- -- ---- -- ---
lpforu lp0 RUNNING 3 /etc/passwd root 1 100 1 1 1
The enable command can also be used to start the print queue. It takes the
printer queue device as its only argument, as in the following example.
# enable lpforu:lp0
14.6 Flushing a print job
You discovered that the first job you printed was the incorrect one. You printed
the correct one but now you want to delete the first job. This is how it would be
done:
1. Check the status of the print queue.
# lpstat -vlpforu
Queue Dev Status Job Files User PP % Blks Cp Rnk
------ ---- -------- --- ---------------- -------- ---- -- ---- -- ---
lpforu lp0 RUNNING 3 /etc/passwd root 1 100 1 1 1
2. Print the /etc/hosts file to the default printer.
# lpr -dlpforu /etc/hosts
3. Check the status of the print queue.
# lpstat -vlpforu
Queue Dev Status Job Files User PP % Blks Cp Rnk
------ ---- -------- --- ---------------- -------- ---- -- ---- -- ---
lpforu lp0 RUNNING 3 /etc/passwd root 1 100 1 1 1
QUEUED 4 /etc/hosts root 1 100 2 1 2
Chapter 14. Printing 405
4. Cancel the print job for /etc/passwd using one of the following commands:
# qcan -P lpforu -x 3
# cancel 3
# lprm -P lpforu 3
# enq -P lpforu -x 3
5. Check the print queue using the qchk command.
# qchk -P lpforu
Queue Dev Status Job Files User PP % Blks Cp Rnk
------ ---- -------- --- ---------------- -------- ---- -- ---- -- ---
lpforu lp0 RUNNING 4 /etc/hosts root 1 100 2 1 2
14.7 How to check the print spooler
There are various commands to check a print spooler. This section covers the
lpstat command and some of the flags you can use. The enq command has a
similar function.
In Table 14-4 are some of the flags used by the lpstat command and, where
available, an equivalent enq command.
Table 14-4 Flags for the lpstat command and enq command equivalents
Flag enq Equivalent Description
-aList enq -q -PQueue1 Provides status and job information on
queues.
-d enq -q Displays the status information for the
system default destination for the lp
command.
-oList Displays the status of print requests or
print queues.
-pList Displays the status of printers.
-r enq -A Provides status and job information on
queues.
-s enq -A Displays a status summary, including a
list of printers and their associated
devices.
-t enq -AL Displays all status information, including a
list of printers and their associated
devices.
406 IBM ^ Certification Study Guide - pSeries AIX System Administration
The following is an example of using the lpstat command with different flag
settings to get the status of the print queue lpforu:
# lpstat -plpforu
Queue Dev Status Job Files User PP % Blks Cp Rnk
------ --- --------- --- ------------------ ---------- ---- -- ----- --- ---
lpforu lp0 RUNNING 2 /etc/hosts root 2 1 1
# lpstat -u"root"
Queue Dev Status Job Files User PP % Blks Cp Rnk
------- --- --------- --- ------------------ ---------- ---- -- ----- --- ---
lpforu lp0 RUNNING 2 /etc/hosts root 2 1 1
The output for the lpstat -t command is the same as the output for the lpstat
-u and lpstat -p commands, except that it gives the queue file, as well as the
time stamp, for the file in the queue.
14.8 Setting the time out on a printer
Setting the time out on a printer specifies the amount of time, in seconds, the
system waits for an operation to complete on a printer. The value must be greater
than zero (0). The default value is calculated based on the device you select.
This option would be used in the following scenarios:
A large network with many users utilizing the printers.
A network with printers a long distance from the server or at another location.
The following example shows output from the lpstat command that indicates the
printer time out should be increased.
# lpstat -plpforu
Queue Dev Status Job Files User PP % Blks Cp Rnk
------- ----- --------- --- ------------------ ---------- ---- -- ----- --- ---
lpforu lp0 DEV_WAIT 17 smit.log root 50 1 1
To increase the printer time out, enter the following SMIT fast path:
smitty spooler
-uList enq -u Prints the status of all print requests for
users specified in List. List is a list of login
names.
-vList Prints the status of printers. The List
variable is a list of printer names.
Flag enq Equivalent Description
410 IBM ^ Certification Study Guide - pSeries AIX System Administration
Once everything is selected, you will go to the Change/Show Printer Connection
Characteristics menu, as displayed in Figure 14-13. Here you select the Printer
TIME OUT period (seconds) and change it, in this case, to 60 seconds.
Figure 14-13 Change/Show Printer Connection Characteristics screen
Chapter 14. Printing 411
Once the command has completed, you will get the COMMAND STAUS menu,
as displayed in Figure 14-14, which shows the status of command completion.
Figure 14-14 Changing printer connection characteristics results
14.9 Basic printer diagnostics checklist
In this section are some troubleshooting tips. This is not a comprehensive list, but
it will assist you with resolving some of the more common problems you may
encounter.
Verify that the qdaemon is running. Make sure there are no forked processes
running from the qdaemon.
Make sure the system date is correct. The qdaemon automatically rebuilds
the /etc/qconfig.bin file when the qconfig file changes. If the date on the
qconfig file is earlier than the date on the /etc/qconfig.bin file, the qconfig file
is not digested, even if it was just modified. Use the enq -Y command to
redigest the qconfig file.
If the dates on the /etc/qconfig.bin file and the /etc/qconfig file are correct, and
changes to the qconfig file are correct, the /etc/qconfig file may no longer be
linked to the /usr/lpd/qconfig file.
412 IBM ^ Certification Study Guide - pSeries AIX System Administration
Check that the /tmp directory is not full. The /tmp directory may be full if you
receive a message, such as No Virtual Printers Defined, or if your are unable
to print from InfoExplorer.
If only the root user can print, check the permissions of the /tmp directory.
Also, check the permissions of the print commands being used (including
enq).
Check for obsolete queue names in the /var/spool/lpd/qdir file. A problem with
the installation of a new /etc/qconfig file occurs when a queue is removed
from the new /etc/qconfig file and a print request is made using the obsolete
queue name. In this case the qdaemon logs an error message. You must
determine if the message refers to an old queue. If so, the problem will persist
until you remove the obsolete queue entries from the /var/spool/lpd/qdir file.
If operator-attention messages requested by remote print commands are not
being received, make sure the socket is connected and the host name can be
pinged.
14.10 Quiz
The following certification assessment question helps verify your understanding
of the topics discussed in this chapter.
1. The Widget Company has installed a new laser printer on their network. The
RS/6000 has been configured to print to that printer using the pcl queue. A
print job was submitted to the pcl queue and was running until the printer ran
out of paper. The printer was offline for 30 minutes before the paper was
added. What needs to be done to continue the print job?
A. enable pcl
B. startsrc -s lpd
C. refresh -s lpd
D. resubmit the job
The following are additional questions created by the authors to further test your
understanding of the topics.
1. To list the print job 120 on printer lineprinter, which command would you use?
A. qchk -P lineprinter
B. qcan 120
C. ps lineprinter
D. lsdev lineprinter | grep 120
Chapter 14. Printing 413
2. To print the file /etc/host to the printer lineprinter, which command would you
use?
A. lpr /etc/hosts -P lineprinter
B. lpstat lineprinter
C. lprm /etc/hosts -P lineprinter
D. print /etc/hosts
14.10.1 Answers
The following answer is for the assessment quiz questions.
1. A
The following answers are for the additional quiz questions.
1. A
2. A
14.11 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Create a new print queue called 3k120.
2. Explain the /etc/qconfig file.
3. Start the print queue 3k120.
4. Stop the print queue 3k120.
5. Change the Time Out on the printer to twice its original Time Out.
6. Check the print queue using four different print commands.
7. Flush a print job.
414 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 415
Chapter 15. Sendmail and e-mail
The mail facility provides a method for exchanging electronic mail between the
users on the same system or on multiple systems connected by a network. This
chapter discusses mail configuration tasks, mail configuration files, mail aliases,
and mail logs.
15
416 IBM ^ Certification Study Guide - pSeries AIX System Administration
15.1 Overview of mail system
The mail system is an internetwork mail delivery facility that consists of a user
interface, a message routing program, and a message delivery program (or
mailer).
A mail user interface enables users to create, send, and receive messages from
other users. The mail system provides two user interfaces, mail and mhmail. The
mail command is the standard mail user interface available on all UNIX systems.
The mhmail command is the Message Handler (MH) user interface, an enhanced
mail user interface designed for experienced users.
A message routing program routes messages to their destinations. The mail
system's message routing program is the sendmail command (a daemon).
Depending on the type of route to the destination, the sendmail command uses
different mailers to deliver messages as shown in Figure 15-1.
Figure 15-1 Overview of mail system
Mail
User Interface
Message
Routing Program Mailers
Sendmail
Daemon
Mail
MH
/etc/sendmail.cf
/etc/aliases
/etc/sendmail.nl
Information
bellmail
local
mailbox
BNU
UUCP
link
remote
mailbox
SMTP
TCP/IP
link
remote
mailbox
Chapter 15. Sendmail and e-mail 417
To deliver local mail, the sendmail program routes messages to the bellmail
program. The bellmail program delivers all local mail by appending messages to
the user's system mailbox, which is in the /var/spool/mail directory.
To deliver mail over a UNIX-to-UNIX Copy Program (UUCP) link, the sendmail
program routes messages using Basic Network Utilities (BNU).
To deliver Transmission Control Protocol/Internet Protocol (TCP/IP)-routed mail,
the sendmail command establishes a TCP/IP connection to the remote system
then uses Simple Mail Transfer Protocol (SMTP) to transfer the message to the
remote system.
Figure 15-2 shows the mail management tasks for a system administrator.
Figure 15-2 Mail management tasks
15.2 Mail daemons
The following is a description of the mail daemons:
Sendmail daemon A message routing program routes messages to their
destinations. The mail system's message routing program is
the sendmail command, which is part of the Base Operating
System (BOS) and is installed with BOS. The sendmail
command is a daemon that uses information in the
/etc/sendmail.cf file, the /etc/aliases file, and the
/etc/sendmail.nl file to perform the necessary routing.
Syslogd daemon The sendmail command logs mail system activity through
the syslogd daemon. The syslogd daemon must be
configured and running for logging to occur. Refer to section
Manage Mail Log
Manage Mail Queue
Customize:
/etc/sendmail.cf
/etc/aliases
System Administrator
/etc/rc.tcpip
418 IBM ^ Certification Study Guide - pSeries AIX System Administration
15.4, “Mail logs” on page 422 for more information about the
syslogd daemon.
15.2.1 Starting the sendmail daemon
To start the sendmail daemon, enter either of the following commands:
startsrc -s sendmail
or
/usr/lib/sendmail
If the sendmail daemon is already active when you enter one of these previous
commands, you will see the following message on the screen:
The sendmail subsystem is already active. Multiple instances are not
supported.
If the sendmail daemon is not already active, then a message indicating that the
sendmail daemon has been started will be generated.
15.2.2 Stopping the sendmail daemon
To stop the sendmail daemon, execute the stopsrc -s command. If the sendmail
daemon was not started with the startsrc command, find the sendmail PID and
then kill the process issuing the following commands:
ps -ef |grep sendmail
kill -9 sendmail_pid
15.2.3 Refreshing the sendmail daemon
To refresh the sendmail daemon, issue the command:
refresh -s sendmail
15.2.4 Getting the status of sendmail daemon
The following example shows how to get the status of the sendmail daemon
using lssrc command with the -s flag. The status can be active or inoperative.
# lssrc -s sendmail
Subsystem Group PID Status
sendmail mail 5422 active
Chapter 15. Sendmail and e-mail 419
15.2.5 Autostart of the sendmail daemon (/etc/rc.tcpip)
To configure the /etc/rc.tcpip file so that the sendmail daemon will be started at
system boot time:
1. Edit the /etc/rc.tcpip file.
2. Find the line that begins with start /usr/lib/sendmail. By default, this line
should be uncommented, that is, there is no # (pound sign) at the beginning
of the line. However, if it is commented, delete the pound sign.
15.2.6 Specifying time values in sendmail (in rc.tcpip)
The interval at which the sendmail daemon processes the mail queue is
determined by the value of the -q flag when the daemon starts. The sendmail
daemon is usually started by the /etc/rc.tcpip file at system startup. The
/etc/rc.tcpip file contains a variable called the queue processing interval (QPI),
which it uses to specify the value of the -q flag when it starts the sendmail
daemon. By default, the value of QPI is 30 minutes. To specify a different queue
processing interval:
1. Edit the /etc/rc.tcpip file.
2. Find the line that assigns a value to the qpi variable, such as: qpi=30m
3. Change the value assigned to the qpi variable to the time value you prefer.
These changes will take effect at the next system restart. For the changes to take
effect immediately, stop and restart the sendmail daemon specifying the new -q
flag value.
15.2.7 Specifying time values in sendmail (not in rc.tcpip)
To set the message time-out and queue processing interval, you must use a
specific format for the time value. The format of a time value is:
-qNumberUnit, where Number is an integer value and Unit is the unit letter. Unit
may have one of the following values:
s Seconds
m Minutes
h Hours
d Days
w Weeks
If Unit is not specified, the sendmail daemon uses minutes (m) as the default.
Here are three examples.
420 IBM ^ Certification Study Guide - pSeries AIX System Administration
To process the queue every 15 days, issue the command:
/usr/sbin/sendmail -q15d
To process the queue every 15 hours, issue the command:
/usr/sbin/sendmail -q15h
To process the queue every 15 minutes, issue the command:
/usr/sbin/sendmail -q15
15.3 Mail queue directory: /var/spool/mqueue
The mail queue is a directory that stores data and controls files for mail
messages that the sendmail command delivers. By default, the mail queue is
/var/spool/mqueue. Mail messages may be queued for several reasons. First, the
sendmail command can be configured to process the queue at certain intervals
rather than immediately. If this is so, mail messages must be stored temporarily.
Second, if a remote host does not answer a request for a mail connection, the
mail system queues the message and tries again later.
15.3.1 Printing the mail queue
The contents of the queue can be printed using the mailq command (or by
specifying the -bp flag with the sendmail command). This produces a listing of
the queue IDs, the size of the message, the date the message entered the
queue, and the sender and recipients.
15.3.2 Mail queue files
The mail queue directory /var/spool/mqueue contains four types of mail queue
files:
Data file
Control file
Temporary file
Transcript file
Each message in the queue has a number of files associated with it. For
example, if a message has a queue ID of AA00269, the following files are
created and deleted in the mail queue directory while the sendmail command
tries to deliver the message:
dfAA00269 Data file
Chapter 15. Sendmail and e-mail 421
qfAA00269 Control file
tfAA00269 Temporary file
xfAA00269 Transcript file
15.3.3 Forcing the mail queue to run
In some cases, the mail queue becomes unresponsive. To force a queue to run,
use the sendmail command with a -q flag (with no value). You can also use the -v
flag (verbose) to watch what happens.
/usr/sbin/sendmail -q -v
15.3.4 Moving the mail queue
When a host goes down for an extended period, many messages routed to (or
through) that host may be stored in your mail queue. As a result, the sendmail
command spends a long time sorting the queue, severely degrading your
system's performance. If you move the queue to a temporary place and create a
new queue, the old queue can be run later when the host returns to service. To
move the queue to a temporary place and create a new queue:
1. Stop the sendmail daemon.
2. Move the entire queue directory by entering:
cd /var/spool
mv mqueue omqueue
3. Restart the sendmail daemon.
4. Process the old mail queue by entering:
/usr/sbin/sendmail -oQ/var/spool/omqueue -q
The -oQ flag specifies an alternate queue directory. The -q flag specifies to
run every job in the queue. To get a report about the progress of the
operation, use the -v flag. This operation can take a long time.
5. Remove the log files and the temporary directory when the queue is empty by
entering:
rm /var/spool/omqueue/*
rmdir /var/spool/omqueue
422 IBM ^ Certification Study Guide - pSeries AIX System Administration
15.4 Mail logs
The sendmail command logs mail system activity through the syslogd daemon.
The syslogd daemon must be configured and running for logging to occur.
Specifically, the /etc/syslog.conf file may contain the uncommented line:
mail.debug /var/spool/mqueue/log
If it does not, use an editor to make this change; be certain that the path name is
correct. If you change the /etc/syslog.conf file while the syslogd daemon is
running, refresh the syslogd daemon by entering the command:
refresh -s syslogd
If the /var/spool/mqueue/log file does not exist, you must create it by entering the
command:
touch /var/spool/mqueue/log
15.4.1 Managing the mail log files
Because information is continually appended to the end of the log file, it can
become very large. Also, error conditions can cause unexpected entries to the
mail queue. To keep the mail queue and log from growing too large, execute the
/usr/lib/smdemon.cleanu shell script. This script forces the sendmail command
to process the queue and maintains four progressively older copies of log files
named log.0, log.1, log.2, and log.3. Each time the script runs, it moves:
1. log.2 to log.3
2. log.1 to log.2
3. log.0 to log.1
4. log to log.0
This allows logging to start over with a new file. Run this script either manually or
at a specified interval with the cron daemon. A typical log file is shown in
Figure 15-3 on page 423. The highlighted field, stat=Deferred refers to a
message that could not get routed to the destination.
Chapter 15. Sendmail and e-mail 423
Figure 15-3 /var/spool/mqueue/log file
15.4.2 Logging mailer statistics
The sendmail command tracks the volume of mail being handled by each of the
mailer programs that interface with it (those mailers defined in the
/etc/sendmail.cf file).
To start the accumulation of mailer statistics, create the /var/tmp/sendmail.st
(refer to the sendmail.cf file for the exact path) file by entering:
touch /var/tmp/sendmail.st
The sendmail command updates the information in the file each time it processes
mail. The size of the file does not grow, but the numbers in the file do. They
represent the mail volume since the time you created or reset the
/var/tmp/sendmail.st file.
15.4.3 Displaying mailer information
The statistics kept in the /var/tmp/sendmail.st file are in a database format that
cannot be read as a text file. To display the mailer statistics, enter the command:
/usr/sbin/mailstats
This reads the information in the /etc/sendmail.st file, formats it, and writes it to
standard output in the format shown in Figure 15-4 on page 424.
424 IBM ^ Certification Study Guide - pSeries AIX System Administration
Figure 15-4 Displaying mailer information
The fields in the report have the following meanings:
msgs_from Contains the number of messages received by the local machine
from the indicated mailer.
bytes_from Contains the number of bytes in the messages received by the
local machine from the indicated mailer.
msgs_to Contains the number of messages sent from the local machine
using the indicated mailer.
bytes_to Contains the number of bytes in the messages sent from the local
machine using the indicated mailer.
15.5 Mail aliasing and forwarding
Aliases map names to address lists. The aliases are defined in the /etc/aliases
file by the user administrator. The /etc/aliases file consists of a series of entries in
the following format:
Alias: Name1, Name2, ... NameX
Chapter 15. Sendmail and e-mail 425
where Alias can be any alphanumeric string that you choose (not including
special characters, such as @ or !). Name1 through NameX is a series of one or
more recipient names. The /etc/aliases file must contain the following three
aliases (a sample file is shown in Figure 15-5):
MAILER-DAEMON
postmaster
nobody
Figure 15-5 /etc/aliases File
15.5.1 Creating or modifying local system aliases
To add the programer alias for four users working together in the same
department (John, Smith, Mary, Bob), perform the following functions:
1. Edit the /etc/aliases file.
2. On a blank line, add an alias, followed by a colon (:), followed by a list of
comma-separated recipients. For example, the following entry defines an
alias named programer to be the names of the people in that group.
programer: john, smith, mary@sv1051c, bob@sv1051c
426 IBM ^ Certification Study Guide - pSeries AIX System Administration
3. Create an owner for any distribution list aliases. If the sendmail command has
trouble sending mail to the distribution list, it sends an error message to the
owner of that list. For example, the owner of the above list is root of system
sv1051a and is defined by the following entry in the /etc/aliases file:
owner-programer: root@sv1051a
4. Recompile the /etc/aliases file, as described in Section 15.5.2, “Building the
alias database” on page 426.
15.5.2 Building the alias database
The sendmail command does not directly use the alias definitions in the local
system /etc/aliases file. Instead, the sendmail command reads a processed
database manager (dbm) version of the /etc/aliases file. You can compile the
alias database using the following method.
Run the /usr/sbin/sendmail command using the -bi flag or run newaliases. This
command causes the sendmail command to read the local system /etc/aliases
file and creates two additional files containing the alias database information:
/etc/aliases.dir
/etc/aliases.pag
After you have completed building the alias database, you can use the alias
(programer) to send mail to the users (smith and john) on the local system and
the users (mary and bob) on system sv1051c by using the mail command as
shown below:
mail programer
15.5.3 Forwarding mail with /etc/aliases
The /etc/aliases file also allows the automatic forwarding of mail to other systems
or to other users on the system. This can be helpful, for example, if you are
administering large amounts of systems and need a common address to place
the mail for root from every system. To do this, place an entry in /etc/aliases in
the following format:
User: Name1, Name2, ... NameX
where User is a user ID that exists on the system and Name1 through NameX is
a list of names to which mail is to be forwarded.
For example, if the mail for root was to be forwarded to Smith and Bob, on a blank
line in /etc/aliases, you would enter:
root: smith, bob@sv1051c
Chapter 15. Sendmail and e-mail 427
By doing this, however, root would no longer receive any mail. If you want to have
a user retain a copy of its mail and still forward mail to other systems or users on
the same system, place an entry in /etc/aliases in the following format:
User: \User, Name1, Name2, ... NameX
The backslash (\) instructs sendmail to keep a copy of mail for User, and send
copies to Name1 through NameX. If the backslash were omitted, this would
create an infinite forwarding loop and could lead to mail flooding for all the names
in the list.
For example, if the mail for root was to be forwarded to Smith and Bob, and root
was to retain a copy, in /etc/aliases you would enter:
root: \root, smith, bob@sv1051c
After /etc/aliases has been modified, the /usr/sbin/sendmail -bi or newaliases
command must be run for the changes to take effect, as described in
Section 15.5.2, “Building the alias database” on page 426.
15.5.4 Forwarding mail with $HOME/.forward
By creating a file named .forward in a user’s home directory, mail can also be
forwarded to other systems or other users on a system. This is a useful option for
users on a system that cannot edit the /etc/aliases file. The .forward file uses the
following format:
Name1, Name2, ... NameX
where Name1 through NameX is a list of names to which mail is to be forwarded.
For example, if John wants to forward his mail to Smith and Mary, he would do
the following:
vi $HOME/.forward
This will allow him to create the .forward file in his home directory through vi. On
a blank line he would enter:
smith, mary@sv1051c
Then, he would save and quit the file. If John wants to retain a copy of his mail,
he would place a backslash (\) and his own user ID in the .forward file:
\john, smith, mary@sv1051c
The sendmail -bi or newaliases command does not have to be run for the
changes to take effect.
428 IBM ^ Certification Study Guide - pSeries AIX System Administration
Any modifications to the .forward file become effective as soon as the file is
saved. To stop mail forwarding, delete the .forward file:
rm $HOME/.forward
15.5.5 Forwarding mail to /dev/null
To automatically delete mail for a particular user ID, mail can be forwarded to
/dev/null in /etc/aliases or $HOME/.forward. This can be helpful, for example, for
users who do not need to actively check their mail. To do this in /etc/aliases, you
would enter:
User: /dev/null
where User is the user ID that will have its mail automatically deleted. Then you
would run sendmail -bi or newaliases to have the changes take effect.
To do this in $HOME/.forward, you would enter:
/dev/null
15.6 Mail addressing
Mail is sent to a user’s address. How you address mail to another user depends
upon the user’s location with respect to your system. The address would depend
on whether you are sending the mail:
To users on your local system.
To users on your network.
To users on a different network.
Over a BNU or UUCP link.
15.6.1 To address mail to users on your local system
To send a message to a user on your local system (to someone whose login
name is listed in your /etc/passwd file), use the login name for the address. At
your system command line prompt, you can use the mail command in the way
shown in the following example:
mail LoginName
If smith is on your system and has the login name smith, use the command:
mail smith
Chapter 15. Sendmail and e-mail 429
15.6.2 To address mail to users on your network
To send a message through a local network to a user on another system, at the
command line enter:
mail LoginName@SystemName
For example, if john is on system sv1051c, use the following command to create
and send a message to him:
mail john@sv1051c
15.6.3 To address mail to users on a different network
If your network is connected to other networks, you can send mail to users on the
other networks. The address parameters differ depending on how your network
and the other networks address each other and how they are connected.
Using a central database of names and addresses:
Use the mail command in the way shown in the following example:
mail LoginName@SystemName
Using domain name addressing
Use the mail command in the ways shown in the following examples:
mail LoginName@SystemName.DomainName
For example, to send mail to a user john, who resides in a remote network with a
domain name in.ibm.com, use the following command:
mail j[email protected]m.com
15.6.4 To address mail over a BNU or UUCP link
To send a message to a user on another system connected to your system by the
Basic Networking Utilities (BNU) or another version of UNIX-to-UNIX Copy
Program (UUCP), you must know the login name, the name of the other system,
and the physical route to that other system.
When your computer has a BNU or UUCP link, you can use the command as
shown in the following.
mail UUCPRoute!LoginName
When the BNU or UUCP link is on another computer, use the mail command, as
shown below:
mail @InternetSystem:UUCPSystem!username
430 IBM ^ Certification Study Guide - pSeries AIX System Administration
Notice that, in this format, you are not sending mail to a user at any of the
intermediate systems; , no login name precedes the @ in the domain address.
15.7 Storing mail
Mail is stored in different ways depending on the specific situation, as shown in
Figure 15-6 on page 431. The mail program uses the following type of mailboxes
or folders:
System mailbox This resides in /var/spool/mail directory and each system
mailbox is named by the user ID associated with it. For
example, if the user ID is smith, the system mailbox is
/var/spool/mail/smith. When the mail arrives for any user ID,
it is placed in the respective system mailbox. The shell
checks for the new mail and issues the following message
when the user logs in: YOU HAVE NEW MAIL
Personal mailbox Each user has a personal mailbox. When the mail is read
using the mail command by the user, and if it is not saved in
a file or deleted, it is written to user’s personal mailbox,
$HOME/mbox ($HOME is the default login directory). For
user ID smith, the personal mailbox is /home/smith/mbox.
dead.letter file If the user interrupts the message being created to complete
some other tasks, the system saves the incomplete message
in the dead.letter file in the user’s home directory ($HOME).
For user ID smith, /home/smith/dead.letter is the dead.letter
file.
Folders To save a message in an organized fashion, users can use
folders. Messages can be put into a user’s personal folder
from the system mailbox or the personal mailbox as shown in
Figure 15-6 on page 431.
The mail command can be used with various flags as shown below:
mail Displays the system mailbox.
mail -f Displays your personal mailbox (mbox).
mail -f+folder Displays a mail folder.
mail user@address Addresses a message to the specified user.
Chapter 15. Sendmail and e-mail 431
Figure 15-6 Message path for mail
System Mail Box
/var/spool/mail/userid
Personal Mail Box
/home/userid/mbox
Incoming Mail
Personal Folder
Optional
Mail Queue Directory
/var/spool/mqueue
Outgoing mail
If interrupted
MAIL LOGS
/var/spool/mqueue/log
User writes a mail
/home/userid/dead.letter
User reads the mail
for delivery
432 IBM ^ Certification Study Guide - pSeries AIX System Administration
15.8 Mail administrator’s reference
This section provides a quick reference to the various mail commands, files, and
directories.
15.8.1 List of mail commands
This list includes commands for using and managing the mail program.
mailq Prints the contents of the mail queue.
mailstats Displays statistics about mail traffic.
newaliases Builds a new copy of the alias database from the
/etc/aliases file.
sendmail Routes mail for local or network delivery.
smdemon.cleanu Cleans up the sendmail queue for periodic housekeeping.
15.8.2 List of mail files and directories
This list of files and directories is arranged by function.
Using the mail program
$HOME/.mailrc Enables the user to change the local system defaults for
the mail program.
$HOME/mbox Stores processed mail for the individual user.
/usr/bin/Mail,
/usr/bin/mail, and
/usr/bin/mailx Specifies three names linked to the same program. The
mail program is one of the user interfaces to the mail
system.
/var/spool/mail Specifies the default mail drop directory. By default, all
mail is delivered to the /var/spool/mail/UserName file.
/var/spool/mqueue Contains the log file and temporary files associated with
the messages in the mail queue.
Using the sendmail command
/usr/sbin/sendmail The sendmail command.
/usr/ucb/mailq Links to the /usr/sbin/sendmail. Using mailq is
equivalent to using the /usr/sbin/sendmail -bp
command.
Chapter 15. Sendmail and e-mail 433
/usr/ucb/newaliases Links to the /usr/sbin/sendmail file. Using
newaliases is equivalent to using the
/usr/sbin/sendmail -bi command.
/usr/sbin/mailstats Formats and prints the sendmail statistics as found
in the /etc/sendmail.st file, if it exists. The
/etc/sendmail.st file is the default, but you can
specify an alternative file.
/etc/aliases Describes a text version of the aliases file for the
sendmail command. You can edit this file to create,
modify, or delete aliases for your system.
/etc/sendmail.cf Contains the sendmail configuration information in
text form. Edit the file to change this information.
/etc/sendmail.cfDB Contains the processed version of the
/etc/sendmail.cf configuration file. This file is created
from the /etc/sendmail.cf file when you run the
/usr/sbin/sendmail -bz command.
/etc/sendmail.nl Contains the sendmail National Language Support
(NLS) configuration information in text form. Edit the
file to change this information.
/usr/lib/smdemon.cleanu Specifies a shell file that runs the mail queue and
maintains the sendmail log files in the
/var/spool/mqueue directory.
/var/tmp/sendmail.st Collects statistics about mail traffic. This file does not
grow. Use the /usr/sbin/mailstats command to
display the contents of this file.
/var/spool/mqueue Describes a directory containing the temporary files
associated with each message in the queue. The
directory can contain the log file.
434 IBM ^ Certification Study Guide - pSeries AIX System Administration
15.9 Quiz
The following are questions created by the authors to further test your
understanding of the topics.
1. A Company would like to create an e-mail alias on an AIX workstation that will
forward e-mail to a user on another workstation for collection of data. The
system administrator would like to add this entry to the /etc/aliases file. Which
of the following actions should be performed in order for the change to take
affect?
A. Reboot the workstation.
B. Run the mailq command.
C. Stop and start TCP/IP.
D. Use the sendmail command.
2. A system administrator wants to process a mail queue after every 45 minutes.
Which of the following commands should be used if the change must take
effect immediately and be permanent?
A. sendmail -q45d
B. sendmail -q45h and also edit /etc/rc.tcpip to change qpi=45h
C. sendmail -q45 and also edit /etc/rc.tcpip to change qpi=45m
D. sendmail -q45
3. All mail sent to root on system mars needs to be redirected to user
administrator on system earth. Prior to running the newaliases command,
which command should be run to accomplish this goal?
A. On system earth, run the command: echo "mars: earth" >> /etc/hosts
B. On system mars, run the command: echo "root:admin@earth" >>
/etc/aliases
C. On system mars, run the command: echo "root:admin@earth" >>
/etc/sendmail.cf
D. On system earth, run the command: echo "root:admin@earth" >>
/etc/sendmail.cf
Chapter 15. Sendmail and e-mail 435
15.9.1 Answers
The following answers are for the quiz questions.
1. D
2. C
3. B
15.10 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Display the status of the sendmail daemon on your system. If it is not active,
start the sendmail daemon.
2. Locate the entry in the /etc/rc.tcpip file that starts the sendmail daemon at
system boot time.
3. Customize the sendmail daemon to process the mail queue every 45 minutes.
Make this change take effect immediately.
4. Create an alias for all the users in your department and compile the alias
database. Compile the database.
5. Stop the sendmail daemon.
436 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 437
Chapter 16. Online documentation
AIX Version 4.3, and later versions, provide an optionally installable component
for Web based documentation, the Documentation Search Service. It allows you
to search online HTML documents. It provides a search form that appears in your
Web browser. When you type words into the search form, it searches for the
words and then presents a search results page that contains links that lead to the
documents that contain the target words.
You can set up one of your AIX systems in your organization to be the
documentation server and all other systems as documentation clients. This will
allow documentation to be installed on only one system, and all other systems
can access this system without needing the documentation installed locally.
You need the following products and components installed for a complete set of
services.
For the client:
a. A Web browser
b. The bos.docsearch.client.* filesets (for AIX integration)
For the documentation server (which may also act as a client)
a. The entire bos.docsearch package
b. The documentation libraries
c. A Web browser
16
438 IBM ^ Certification Study Guide - pSeries AIX System Administration
d. A Web server
The browser must be a forms-capable browser, and the Web server must be
CGI-compliant.
If you are planning on integrating your own documentation on the documentation
server, you will also need to build the document's indexes.
Except for the end-user tasks described in Section 16.6, “Invoking
Documentation Search Service” on page 443, you need root authority to perform
the installation and configuration tasks.
There are a variety of ways to install the documentation, Web server, and
Document Search Service. You can use the Configuration Assistant TaskGuide,
Web-Based Systems Management, or SMIT.
The easiest way for a non-technical user to install and configure Documentation
Search Services is by using the Configuration Assistant TaskGuide. To run the
Configuration Assistant TaskGuide, use the configassist command, then select
the item titled Configure Online Documentation and Search.
If you would rather install Documentation Search Services manually, you can use
SMIT.
Chapter 16. Online documentation 439
16.1 Installing the Web browser
Use smitty install_latest to install Netscape, supplied on the AIX Version 4.3
or later Bonus Pack CD-ROM. Use smit list_installed to check whether you
have the following filesets installed as shown in Figure 16-1.
Figure 16-1 Netscape filesets
If you are installing the Netscape browser from other sources, or you are
installing other Web browsers, follow the installation instructions that come with
the software. Note that there will not be any records in the ODM if your product
source is not in installp format.
440 IBM ^ Certification Study Guide - pSeries AIX System Administration
16.2 Installing the Web server
You may install any CGI-compliant Web Server. The Lotus Domino Go
Webserver is used here. It is supplied on one of the AIX Version 4.3 or later
Bonus Pack CD-ROMs.
The Documentation Search Service uses its own search engine CGIs. Therefore,
you do not need to install the NetQ fileset. Figure 16-2 shows the filesets
installed.
Figure 16-2 Domino Go Webserver filesets
If you are installing the Domino Go Webserver from other sources, or you are
installing another Web server, follow the installation instructions that come with
the software. Note that there will not be any records in the ODM if your product
source is not in installp format.
16.3 Installing Documentation Search Service
The documentation search service is (at the time of writing) on the AIX Version
4.3 and later installation CD-ROMs. Install the client portions for a client AIX
image or install the entire bos.docsearch package for a documentation server.
Chapter 16. Online documentation 441
The following filesets are the prerequisite for other documentation search service
filesets (such as IMNSearch):
bos.docsearch.client.Dt
bos.docsearch.client.com
bos.docsearch.rte
For the documentation clients, you need only a Web browser. Installation of the
bos.docsearch.client fileset will give you the CDE desktop icon and the
docsearch command. Refer to Section 16.6, “Invoking Documentation Search
Service” on page 443 for further details.
Use smit list_installed to check whether you have the following filesets
installed, as shown in Figure 16-3.
Figure 16-3 Documentation Search Service filesets
16.4 Configuring Documentation Search Service
Use either wsm or smitty to configure the documentation search service. If you
used the Configuration Assistant TaskGuide to install and configure the
Documentation Search Service, you will not need to perform any further
configuration.
442 IBM ^ Certification Study Guide - pSeries AIX System Administration
For wsm, double-click on the Internet Environment icon, or you can use smit
web_configure to configure the following:
Change / Show Default Browser
Type the command that launches the browser that you want to be the default
browser for all users on this computer; for example, /usr/prod/bin/netscape.
This will set the /etc/environment variable DEFAULT_BROWSER to the string
you type in.
Change Documentation and Search Server
You can define the documentation search server location to be:
– None - disabled
– Remote computer
Type the remote documentation server name. The default TCP/IP port
address is 80. Change it to the port address used by the documentation
server.
– Local - this computer
If you are using Lotus Domino Go Webserver or IBM Internet Connection
Server in the default location, all the default settings of the cgi-bin directory
and HTML directory will have been filled in for you. If you are using other
Web servers, or you are not using the default location, you have to fill in
your cgi-bin directory and HTML directory that the Web server requires.
You may change the port address used by the server. If you change the
port address, you have to use the same address for all your
documentation clients.
16.5 Installing online manuals
You can either install the documentation information onto the hard disk or mount
the documentation CD-ROM in the CD-ROM drive. Mounting the CD-ROM will
save some amount of hard disk space, but it requires the CD-ROM to be kept in
the CD-ROM drive at all times. Also, searching the documentation from the
CD-ROM drive can be significantly slower (in some cases up to 10 times slower)
than searching the information if it is installed on a hard disk. In addition, there
are two documentation CD-ROMs:
The AIX Base Documentation CD-ROM
The AIX Extended Documentation CD-ROM
Chapter 16. Online documentation 443
Use smit install_latest to install the online manuals onto the hard disk. The
fileset bos.docregister is a prerequisite for all online manuals. It will be
automatically installed the first time you install any online manuals even if you
have not selected this fileset.
16.6 Invoking Documentation Search Service
You must log out and log in again after the Documentation Search Service has
been configured so that you will pick up the environment variables set up during
the configuration.
If you are running the CDE desktop environment, double-click the Documentation
Search Service icon in the Application Manager window.
Alternatively, you can use the command docsearch to invoke the documentation
search service. Your Web browser will start, and you should see the
Documentation Search Service page. Netscape is used as the default Web
browser for this discussion.
You can invoke the Documentation Search Service without installing the
docsearch client component. You do not even need to invoke the documentation
search service from an AIX machine. You can do this by first invoking the browser
and entering the following URL:
http://server_name[:port_number]/cgi-bin/ds_form
This URL points to a global search form on the document server where the name
of the remote server is given in server_name. The port_number only needs to be
entered if the port is different from 80.
If you have not run Netscape previously, a series of informational messages and
windows will be shown while Netscape is setting up the environment in your
home directory. This is standard behavior for the first use of Netscape. The
messages will not be shown again the next time you start Netscape.
Note: The installation images located on the AIX Version 4.3 or later Base
Documentation and Extended Documentation CD-ROMs do not contain the
HTML files. These files exist separately on the CD-ROM to allow access
from non-AIX platforms. Installing the images from the CD-ROM will work
correctly; however, copying the installation images by themselves to
another location is not enough for a proper install.
444 IBM ^ Certification Study Guide - pSeries AIX System Administration
The top part of the Documentation Search Service page allows you to specify
your search criteria, and the bottom part shows which online manuals have been
installed. Figure 16-4 shows the documentation search service page with only
the command reference manuals and the programming guide manuals installed.
Figure 16-4 Documentation Search Service
If you have a problem starting the Documentation Search Service, check the
following environment variables. These environment variables may be set,
displayed, and changed using SMIT. Start SMIT, select System Environments,
then select Internet and Documentation Services.
On the client machine:
a. Invoke the Web browser manually and enter the URL
http://server_name[:port_number]/cgi-bin/ds_form to ensure that the server
is up and running.
Chapter 16. Online documentation 445
b. Ensure the DEFAULT_BROWSER variable is set to the command for
starting your Web browser.
Use the command echo $DEFAULT_BROWSER to find out the command used
in starting the browser. Test whether that command can bring up the
browser by manually entering it on the command line.
c. Ensure the DOCUMENT_SERVER_MACHINE_NAME variable is set to
the document server’s host name or IP address.
d. Ensure the DOCUMENT_SERVER_PORT variable is set to the port
address used by the document server’s port address.
On the server machine:
a. Ensure the DEFAULT_BROWSER variable is set to the command for
starting your Web browser.
Use the command echo $DEFAULT_BROWSER to find out the command used
in starting the browser. Test whether that command can bring up the
browser by manually entering it on the command line.
b. Ensure the DOCUMENT_SERVER_MACHINE_NAME variable is set to
the local host name.
c. Ensure the DOCUMENT_SERVER_PORT variable is set to the port
address used by the local Web server.
d. Ensure that the CGI_DIRECTORY variable is set to the correct cgi-bin
directory used by the local Web server.
e. Ensure that the DOCUMENT_DIRECTORY is set to the directory where
the symbolic links doc_link and ds_images reside. If you have not changed
the default, it should be in /usr/lpp/internet/server_root/pub for both IBM
Internet Connection Server and Lotus Domino Go Web Server.
f. If you are not using the default directory, ensure that you have defined the
necessary directory mapping in your Web server configuration file so that
the directory can be resolved.
446 IBM ^ Certification Study Guide - pSeries AIX System Administration
16.7 Quiz
The following are questions created by the authors to further test your
understanding of the topics.
1. By installing the Documentation Search Services client fileset, the following
will be made available to your AIX Version 4.3 system:
A. CDE icon
B. Web browser
C. docsearch command and CDE icon
D. info command and CDE icon
2. From a forms-capable Web browser, the URL used to access the online
documentation server on an AIX Version 4.3 system is:
A. http://server_name[:port_number]/cgi-bin/ds_form
B. http://server_name[:port_number]/cgi-bin/docsearch
C. http://server_name[:port_number]/cgi-bin/info
D. http://server_name[:port_number]/cgi-bin/man
16.7.1 Answers
The following answers are for the quiz questions.
1. C
2. A
16.8 Exercise
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Install a Web browser.
2. Install a Web server.
3. Install the Document Search Services fileset.
4. Install some online manuals.
5. Configure the document search service.
6. Access the online manuals using the docsearch command and from a Web
browser on other systems.
© Copyright IBM Corp. 2001 447
Chapter 17. The AIXwindows font server
XFS is the AIXwindows font server subsystem (prior to AIX Version 4.3, it was
named fs) that supplies fonts to AIXwindows display servers. In the following
sections, topics related to administration of the font server are discussed.
17
Note: To use the AIXwindows font server, the X11.fnt.fontserver fileset must
be installed.
448 IBM ^ Certification Study Guide - pSeries AIX System Administration
17.1 XFS server interrupts
The xfs server responds to the following signals:
SIGTERM Causes the font server to exit cleanly.
SIGUSR1 Causes the server to re-read its configuration file.
SIGUSR2 Causes the server to flush any cached data it may have.
SIGHUP Causes the server to reset, closing all active connections and
re-reads the configuration file.
The server is usually run by a system administrator and started by way of boot
files, such as /etc/rc.tcpip. Users may also wish to start private font servers for
specific sets of fonts.
The configuration language is a list of keyword and value pairs. Each keyword is
followed by an = (equal sign) and the desired value.
17.2 XFS keywords
Table 17-1 shows recognized keywords and the types and descriptions of valid
values.
Table 17-1 XFS keywords
Keyword Description
# A comment character when located in the first column.
catalogue (List of string) Ordered list of font path element names. The current
implementation only supports a single catalogue ("all")
containing all of the specified fonts.
alternate-servers (List of
string)
List of alternate servers for this font server.
client-limit (Cardinal) Number of clients that this font server will support before
refusing service. This is useful for tuning the load on each
individual font server.
clone-self (Boolean) Whether this font server should attempt to clone itself
when it reaches the client limit.
default-point-size
(Cardinal)
The default point size (in decipoints) for fonts that do not
specify.
Chapter 17. The AIXwindows font server 449
17.3 XFS form conventions
One of the following forms can be used to name a font server that accepts TCP
connections.
tcp/hostname:port
tcp/hostname:port/cataloguelist
The hostname specifies the name (or decimal numeric address) of the machine
on which the font server is running. The port is the decimal TCP port on which
the font server is listening for connections. The cataloguelist specifies a list of
catalogue names with '+' as a separator. The following are some examples:
tcp/expo.lcs.mit.edu:7100, tcp/18.30.0.212:7101/all
One of the following forms can be used to name a font server that accepts
DECnet connections.
decnet/nodename::font$objname
decnet/nodename::font$objname/cataloguelist
The nodename specifies the name (or decimal numeric address) of the machine
on which the font server is running. The objname is a normal, case-insensitive
DECnet object name. The cataloguelist specifies a list of catalogue names with
'+' as a separator.
default-resolutions
(Series)
Resolutions the server supports by default. This
information may be used as a hint for pre-rendering and
substituted for scaled fonts that do not specify a resolution.
A resolution is a comma-separated pair of x and y
resolutions in pixels per inch. Multiple resolutions are
separated by commas.
error-file (String) File name of the error file. All warnings and errors are
logged here.
port (Cardinal) TCP port on which the server will listen for connections.
The default is 7100.
use-syslog (Boolean) Whether the syslog function (on supported systems) is to
be used for errors.
deferglyphs (String) Sets the mode for delayed fetching and caching of glyphs.
String can be none, meaning deferred glyphs is disabled or
all, meaning deferred glyphs is enabled for all fonts, and
16, meaning deferred glyphs is enabled only for 16-bit
fonts.
Keyword Description
450 IBM ^ Certification Study Guide - pSeries AIX System Administration
17.4 XFS command flags
Table 17-2 displays the flags used by the xfs command.
Table 17-2 Flags for the xfs command
17.5 Font server examples
The following is a sample of the /usr/lib/X11/fs/config file. Any changes made to
the font server are done in this file.
# SCCSID_BEGIN_TAG
# @(#)99 1.2 src/gos/2d/XTOP/programs/xfs/config.cpp, xfontserver,
gos43D, 981
1A_43D 3/10/98 16:02:38
# SCCSID_END_TAG
# font server configuration file
# $XConsortium: config.cpp,v 1.7 91/08/22 11:39:59 rws Exp $
clone-self = on
use-syslog = off
catalogue = /usr/lib/X11/fonts/,/usr/lib/X11/fonts/misc/,/usr/lib/X11/fonts
/75dpi/,/usr/lib/X11/fonts/100dpi/,/usr/lib/X11/fonts/i18n/,/usr/lib/X11/fo
nts/ibm850/,/usr/lib/X11/fonts/TrueType/,/usr/lib/X11/fonts/Type1/
error-file = /usr/lib/X11/fs/fs-errors
# in decipoints
default-point-size = 120
default-resolutions = 75,75,100,100
# The fontserver will default to using port 7100 if not overridden.
# Historically in AIX (4.1 and 4.2) 7500 is used and specified here.
# To restore this default, simply uncomment the following line.
# port = 7500
Once you have made your changes to the /usr/lib/X11/fs/config file you then run
the following:
Flag Description
-cf ConfigurationFile Specifies the configuration file the font server will use.
-ls ListenSocket Specifies a file descriptor that is already set up to be used as
the listen socket. This option is only intended to be used by the
font server itself when automatically spawning another copy of
itself to handle additional connections.
-port Number Specifies the TCP port number on which the server will listen
for connections.
Chapter 17. The AIXwindows font server 451
xfsconf
When this script is run, you can start the fontserver sub process by entering the
following:
startsrc -s xfs
0513-059 The xfs Subsystem has been started. Subsystem PID is 19746.
In this case, the system has given the font server subsystem a PID of 19746.
17.6 Quiz
The following certification assessment question helps verify your understanding
of the topics discussed in this chapter.
1. A system administrator uses the startsrc command to start the font server
and gets the following message:
subsystem not on file
Which of the following is the proper way to make this subsystem available?
A. Run the definesrc -s xfs command.
B. Run the xfsconf script and then run startsrc -s xfs command.
C. The font server can not be controlled by the system resource //controller.
D. Run the startsrc -s xfs command and then refresh -s inetd
command.
17.6.1 Answers
The following answer is for the assessment quiz questions.
1. B
17.7 Exercises
The following exercises provide sample topics for self study. They will help
ensure comprehension of this chapter.
1. Configure and start the font server.
2. Understand the various locations the fonts are located
3. Install a double-byte code page and try to use.
452 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 453
Related publications
The publications listed in this section are considered particularly suitable for a
more detailed discussion of the topics covered in this redbook.
IBM Redbooks
For information on ordering these publications, see “How to get IBM Redbooks”
on page 454.
Communication Solutions Guide for RS/6000 and AIX V4, SG24-4899
IP Network Design Guide, SG24-2580
IBM ^ Certification Study Guide - pServer AIX System Support,
SG24-6199
Understanding IBM ^ pSeries Performance and Sizing, SG24-4810
AIX 5L Differences Guide, SG24-5765
IBM Certification Study Guide: AIX Installation and System Recovery,
SG24-6183
IBM Certification Study Guide: AIX Performance and System Tuning,
SG24-6184
IBM Certification Study Guide: AIX Problem Determination Tools and
Techniques, SG24-6185
IBM Certification Study Guide: AIX Communications, SG24-6186
IBM ^ Certification Study Guide - pSeries HACMP for AIX,
SG24-6187
IBM Certification Study Guide RS/6000 SP, SG24-5348
AIX Logical Volume Manager, From A to Z: Introduction and Concepts,
SG24-5432
AIX 5L AIX Workload Manager (WLM), SG24-5977
Other resources
These publications are also relevant as further information sources:
AIX 5L Version 5.1 Installation Guide, SC23-4374
AIX Version 4.3 Messages Guide and Reference, SC23-4129
454 IBM ^ Certification Study Guide - pSeries AIX System Administration454 IBM ^ Certification Study Guide - pSeries AIX System Administration
You can access all of the AIX documentation through the Internet at the
following URL:
http://www.ibm.com/servers/aix/library
The following types of documentation are located on the documentation
CD-ROM that ships with the AIX operating system:
– User guides
– System management guides
– Application programmer guides
– All commands reference volumes
– Files reference
– Technical reference volumes used by application programmers
Referenced Web sites
These Web sites are also relevant as further information sources:
Main IBM certification URL.
http://www.ibm.com/certify
AIX Essentials CD-ROM.
http://www.ibm.com/services/learning/spotlight/pseries/cdrom.html
Downloadable AIX fixes.
http://service.software.ibm.com
How to get IBM Redbooks
Search for additional Redbooks or Redpieces, view, download, or order hardcopy
from the Redbooks Web site:
ibm.com/redbooks
Also download additional materials (code samples or diskette/CD-ROM images)
from this Redbooks site.
Redpieces are Redbooks in progress; not all Redbooks become Redpieces and
sometimes just a few chapters will be published this way. The intent is to get the
information out much quicker than the formal publishing process allows.
Related publications 455
IBM Redbooks collections
Redbooks are also available on CD-ROMs. Click the CD-ROMs button on the
Redbooks Web site for information about all the CD-ROMs offered, as well as
updates and formats.
456 IBM ^ Certification Study Guide - pSeries AIX System Administration456 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 457
Special notices
References in this publication to IBM products, programs or services do not imply
that IBM intends to make these available in all countries in which IBM operates.
Any reference to an IBM product, program, or service is not intended to state or
imply that only IBM's product, program, or service may be used. Any functionally
equivalent program that does not infringe any of IBM's intellectual property rights
may be used instead of the IBM product, program or service.
Information in this book was developed in conjunction with use of the equipment
specified, and is limited in application to those specific hardware and software
products and levels.
IBM may have patents or pending patent applications covering subject matter in
this document. The furnishing of this document does not give you any license to
these patents. You can send license inquiries, in writing, to the IBM Director of
Licensing, IBM Corporation, North Castle Drive, Armonk, NY 10504-1785.
Licensees of this program who wish to have information about it for the purpose
of enabling: (i) the exchange of information between independently created
programs and other programs (including this one) and (ii) the mutual use of the
information which has been exchanged, should contact IBM Corporation, Dept.
600A, Mail Drop 1329, Somers, NY 10589 USA.
Such information may be available, subject to appropriate terms and conditions,
including in some cases, payment of a fee.
The information contained in this document has not been submitted to any formal
IBM test and is distributed AS IS. The information about non-IBM ("vendor")
products in this manual has been supplied by the vendor and IBM assumes no
responsibility for its accuracy or completeness. The use of this information or the
implementation of any of these techniques is a customer responsibility and
depends on the customer's ability to evaluate and integrate them into the
customer's operational environment. While each item may have been reviewed
by IBM for accuracy in a specific situation, there is no guarantee that the same or
similar results will be obtained elsewhere. Customers attempting to adapt these
techniques to their own environments do so at their own risk.
Any pointers in this publication to external Web sites are provided for
convenience only and do not in any manner serve as an endorsement of these
Web sites.
458 IBM ^ Certification Study Guide - pSeries AIX System Administration
Any performance data contained in this document was determined in a controlled
environment, and therefore, the results that may be obtained in other operating
environments may vary significantly. Users of this document should verify the
applicable data for their specific environment.
This document contains examples of data and reports used in daily business
operations. To illustrate them as completely as possible, the examples contain
the names of individuals, companies, brands, and products. All of these names
are fictitious and any similarity to the names and addresses used by an actual
business enterprise is entirely coincidental.
Reference to PTF numbers that have not been released through the normal
distribution process does not imply general availability. The purpose of including
these reference numbers is to alert IBM customers to specific information relative
to the implementation of the PTF when it becomes available to each customer
according to the normal IBM PTF distribution process.
The following terms are trademarks of other companies:
Tivoli, Manage. Anything. Anywhere.,The Power To Manage., Anything.
Anywhere.,TME, NetView, Cross-Site, Tivoli Ready, Tivoli Certified, Planet Tivoli,
and Tivoli Enterprise are trademarks or registered trademarks of Tivoli Systems
Inc., an IBM company, in the United States, other countries, or both. In
Denmark, Tivoli is a trademark licensed from Kjøbenhavns Sommer - Tivoli A/S.
C-bus is a trademark of Corollary, Inc. in the United States and/or other
countries.
Java and all Java-based trademarks and logos are trademarks or registered
trademarks of Sun Microsystems, Inc. in the United States and/or other
countries.
Microsoft, Windows, Windows NT, and the Windows logo are trademarks of
Microsoft Corporation in the United States and/or other countries.
PC Direct is a trademark of Ziff Communications Company in the United States
and/or other countries and is used by IBM Corporation under license.
ActionMedia, LANDesk, MMX, Pentium and ProShare are trademarks of Intel
Corporation in the United States and/or other countries.
UNIX is a registered trademark in the United States and other countries licensed
exclusively through The Open Group.
SET, SET Secure Electronic Transaction, and the SET Logo are trademarks
Special notices 459
owned by SET Secure Electronic Transaction LLC.
Other company, product, and service names may be trademarks or service
marks of others
460 IBM ^ Certification Study Guide - pSeries AIX System Administration
© Copyright IBM Corp. 2001 461
GAMGPRMASS
ABI Application Binary Interface
AC Alternating Current
ACL Access Control List
AFPA Adaptive Fast Path
Architecture
AH Authentication Header
AIX Advanced Interactive
Executive
ANSI American National Standards
Institute
APAR Authorized Program Analysis
Report
API Application Programming
Interface
ARP Address Resolution Protocol
ASCI Accelerated Strategic
Computing Initiative
ASCII American National Standards
Code for Information
Interchange
ASR Address Space Register
ATM Asynchronous Transfer Mode
AuditRM Audit Log Resource Manager
AUI Attached Unit Interface
AWT Abstract Window Toolkit
BCT Branch on CounT
BFF Backup File Format
BI Business Intelligence
BIND Berkeley Internet Name
Daemon
BIST Built-In Self-Test
BLAS Basic Linear Algebra
Subprograms
BLOB Binary Large Object
Abbreviations and acronyms
BOS Base Operating System
BSC Binary Synchronous
Communications
CAD Computer-Aided Design
CAE Computer-Aided Engineering
CAM Computer-Aided
Manufacturing
CATIA Computer-Graphics Aided
Three-Dimensional
Interactive Application
CCM Common Character Mode
CD Compact Disk
CDE Common Desktop
Environment
CDLI Common Data Link Interface
CD-R CD Recordable
CD-ROM Compact Disk-Read Only
Memory
CE Customer Engineer
CEC Central Electronics Complex
CFD Computational Fluid
Dynamics
CGE Common Graphics
Environment
CHRP Common Hardware
Reference Platform
CISPR International Special
Committee on Radio
Interference
CLIO/S Client Input/Output Sockets
CLVM Concurrent LVM
CMOS Complimentary Metal-Oxide
Semiconductor
CMP Certificate Management
Protocol
462 IBM ^ Certification Study Guide - pSeries AIX System Administration
COFF Common Object File Format
COLD Computer Output to Laser
Disk
CORBA Common Object Request
Broker Architecture
CPU Central Processing Unit
CRC Cyclic Redundancy Check
CSID Character Set ID
CSR Customer Service
Representative
CSS Communication Subsystems
Support
CSU Customer Set-Up
CWS Control Workstation
DAD Duplicate Address Detection
DAS Dual Attach Station
DASD Direct Access Storage Device
DAT Digital Audio Tape
DBCS Double Byte Character Set
DBE Double Buffer Extension
DC Direct Current
DCE Distributed Computing
Environment
DDC Display Data Channel
DDS Digital Data Storage
DE Dual-Ended
DES Data Encryption Standard
DFL Divide Float
DFP Dynamic Feedback Protocol
DFS Distributed File System
DHCP Dynamic Host Configuration
Protocol
DIMM Dual In-Line Memory Module
DIP Direct Insertion Probe
DIT Directory Information Tree
DIVA Digital Inquiry Voice Answer
DLT Digital Linear Tape
DMA Direct Memory Access
DMT Directory Management Tool
DN Distinguished Name
DNS Domain Naming System
DOE Department of Energy
DOI Domain of Interpretation
DOS Disk Operating System
DPCL Dynamic Probe Class Library
DRAM Dynamic Random Access
Memory
DS Differentiated Service
DSA Dynamic Segment Allocation
DSE Diagnostic System Exerciser
DSMIT Distributed SMIT
DSU Data Service Unit
DTE Data Terminating Equipment
DW Data Warehouse
EA Effective Address
EC Engineering Change
ECC Error Checking and
Correcting
EEPROM Electrically Erasable
Programmable Read Only
Memory
EFI Extensible Firmware Interface
EHD Extended Hardware Drivers
EIA Electronic Industries
Association
EISA Extended Industry Standard
Architecture
ELA Error Log Analysis
ELF Executable and Linking
Format
EMU European Monetary Union
EOF End of File
EPOW Environmental and Power
Warning
Abbreviations and acronyms 463
ERRM Event Response resource
manager
ESID Effective Segment ID
ESP Encapsulating Security
Payload
ESSL Engineering and Scientific
Subroutine Library
ETML Extract, Transformation,
Movement, and Loading
F/C Feature Code
F/W Fast and Wide
FC Fibre Channel
FCAL Fibre Channel Arbitrated Loop
FCC Federal Communication
Commission
FCP Fibre Channel Protocol
FDDI Fiber Distributed Data
Interface
FDPR Feedback Directed Program
Restructuring
FDX Full Duplex
FIFO First In/First Out
FLASH EPROM Flash Erasable
Programmable Read-Only
Memory
FLIH First Level Interrupt Handler
FMA Floating point Multiply Add
operation
FPR Floating Point Register
FPU Floating Point Unit
FRCA Fast Response Cache
Architecture
FRU Field Replaceable Unit
FSRM File System Resource
Manager
FTP File Transfer Protocol
GAI Graphic Adapter Interface
GAMESS General Atomic and
Molecular Electronic Structure
System
GPFS General Parallel File System
GPR General-Purpose Register
GUI Graphical User Interface
GUID Globally Unique Identifier
HACMP High Availability Cluster Multi
Processing
HACWS High Availability Control
Workstation
HCON IBM AIX Host Connection
Program/6000
HDX Half Duplex
HFT High Function Terminal
HIPPI High Performance Parallel
Interface
HiPS High Performance Switch
HiPS LC-8 Low-Cost Eight-Port High
Performance Switch
HostRM Host Resource Manager
HPF High Performance FORTRAN
HPSSDL High Performance
Supercomputer Systems
Development Laboratory
HTTP Hypertext Transfer Protocol
Hz Hertz
I/O Input/Output
I
2
C Inter Integrated-Circuit
Communications
IAR Instruction Address Register
IBM International Business
Machines
ICCCM Inter-Client Communications
Conventions Manual
ICE Inter-Client Exchange
ICElib Inter-Client Exchange library
ICMP Internet Control Message
Protocol
464 IBM ^ Certification Study Guide - pSeries AIX System Administration
ID Identification
IDE Integrated Device Electronics
IDS Intelligent Decision Server
IEEE Institute of Electrical and
Electronics Engineers
IETF Internet Engineering Task
Force
IHV Independent Hardware
Vendor
IIOP Internet Inter-ORB Protocol
IJG Independent JPEG Group
IKE Internet Key Exchange
ILS International Language
Support
IM Input Method
INRIA Institut National de Recherche
en Informatique et en
Automatique
IP Internetwork Protocol (OSI)
IPL Initial Program Load
IPSec IP Security
IrDA Infrared Data Association
(which sets standards for
infrared support including
protocols for data
interchange)
IRQ Interrupt Request
IS Integrated Service
ISA Industry Standard
Architecture, Instruction Set
Architecture
ISAKMP Internet Security Association
Management Protocol
ISB Intermediate Switch Board
ISDN Integrated-Services Digital
Network
ISMP InstallSheild Multi-Platform
ISNO Interface Specific Network
Options
ISO International Organization for
Standardization
ISV Independent Software Vendor
ITSO International Technical
Support Organization
JBOD Just a Bunch of Disks
JDBC Java Database Connectivity
JFC Java Foundation Classes
JFS Journaled File System
JTAG Joint Test Action Group
KDC Key Distribution Center
L1 Level 1
L2 Level 2
L3 Level 3
LAN Local Area Network
LANE Local Area Network
Emulation
LAPI Low-Level Application
Programming Interface
LDAP Lightweight Directory Access
Protocol
LDIF LDAP Directory Interchange
Format
LED Light Emitting Diode
LFD Load Float Double
LFT Low Function Terminal
LID Load ID
LLNL Lawrence Livermore National
Laboratory
LP Logical Partition
LP64 Long-Pointer 64
LPI Lines Per Inch
LPP Licensed Program Product
LPR/LPD Line Printer/Line Printer
Daemon
LRU Least Recently Used
LTG Logical Track Group
LV Logical Volume
Abbreviations and acronyms 465
LVCB Logical Volume Control Block
LVD Low Voltage Differential
LVM Logical Volume Manager
MAP Maintenance Analysis
Procedure
MASS Mathematical Acceleration
Subsystem
MAU Multiple Access Unit
MBCS Multi-Byte Character Support
Mbps Megabits Per Second
MBps Megabytes Per Second
MCA Micro Channel Architecture
MCAD Mechanical Computer-Aided
Design
MDI Media Dependent Interface
MES Miscellaneous Equipment
Specification
MFLOPS Million of FLoating point
Operations Per Second
MII Media Independent Interface
MIP Mixed-Integer Programming
MLR1 Multi-Channel Linear
Recording 1
MMF Multi-Mode Fibre
MODS Memory Overlay Detection
Subsystem
MP Multiprocessor
MPC-3 Multimedia PC-3
MPI Message Passing Interface
MPOA Multiprotocol over ATM
MPP Massively Parallel Processing
MPS Mathematical Programming
System
MST Machine State
MTU Maximum Transmission Unit
MWCC Mirror Write Consistency
Check
MX Mezzanine Bus
NBC Network Buffer Cache
NCP Network Control Point
ND Neighbor Discovery
NDP Neighbor Discovery Protocol
NFB No Frame Buffer
NFS Network File System
NHRP Next Hop Resolution Protocol
NIM Network Installation
Management
NIS Network Information System
NL National Language
NLS National Language Support
NT-1 Network Terminator-1
NTF No Trouble Found
NTP Network Time Protocol
NUMA Non-Uniform Memory Access
NUS Numerical Aerodynamic
Simulation
NVRAM Non-Volatile Random Access
Memory
NWP Numerical Weather Prediction
OACK Option Acknowledgment
OCS Online Customer Support
ODBC Open DataBase Connectivity
ODM Object Data Manager
OEM Original Equipment
Manufacturer
OLAP Online Analytical Processing
OLTP Online Transaction
Processing
ONC+ Open Network Computing
OOUI Object-Oriented User
Interface
OSF Open Software Foundation,
Inc.
OSL Optimization Subroutine
Library
466 IBM ^ Certification Study Guide - pSeries AIX System Administration
OSLp Parallel Optimization
Subroutine Library
P2SC POWER2 Single/Super Chip
PAM Pluggable Authentication
Mechanism
PAP Privileged Access Password
PBLAS Parallel Basic Linear Algebra
Subprograms
PCI Peripheral Component
Interconnect
PDT Paging Device Table
PDU Power Distribution Unit
PE Parallel Environment
PEDB Parallel Environment
Debugging
PEX PHIGS Extension to X
PFS Perfect Forward Security
PGID Process Group ID
PHB Processor Host Bridges
PHY Physical Layer
PID Process ID
PII Program Integrated
Information
PIOFS Parallel Input Output File
System
PKR Protection Key Registers
PMTU Path MTU
POE Parallel Operating
Environment
POP Power-On Password
POSIX Portable Operating Interface
for Computing Environments
POST Power-On Self-test
POWER Performance Optimization
with Enhanced Risc
(Architecture)
PPC PowerPC
PPM Piecewise Parabolic Method
PPP Point-to-Point Protocol
PREP PowerPC Reference Platform
PSE Portable Streams
Environment
PSSP Parallel System Support
Program
PTF Program Temporary Fix
PTPE Performance Toolbox Parallel
Extensions
PV Physical Volume
PVC Permanent Virtual Circuit
QoS Quality of Service
QP Quadratic Programming
RAID Redundant Array of
Independent Disks
RAM Random Access Memory
RAN Remote Asynchronous Node
RAS Reliability, Availability, and
Serviceability
RDB Relational DataBase
RDBMS Relational Database
Management System
RDISC ICMP Router Discovery
RDN Relative Distinguished Name
RDP Router Discovery Protocol
RFC Request for Comments
RIO Remote I/O
RIP Routing Information Protocol
RIPL Remote Initial Program Load
RISC Reduced Instruction-Set
Computer
RMC Resource Monitoring and
Control
ROLTP Relative Online Transaction
Processing
RPA RS/6000 Platform
Architecture
Abbreviations and acronyms 467
RPA RS/6000 Platform
Architecture
RPC Remote Procedure Call
RPL Remote Program Loader
RPM Red Hat Package Manager
RSC RISC Single Chip
RSCT Reliable Scalable Cluster
Technology
RSE Register Stack Engine
RSVP Resource Reservation
Protocol
RTC Real-Time Clock
RVSD Recoverable Virtual Shared
Disk
SA Secure Association
SACK Selective Acknowledgments
SAN Storage Area Network
SAR Solutions Assurance Review
SAS Single Attach Station
SBCS Single-Byte Character
Support
ScaLAPACK Scalable Linear Algebra
Package
SCB Segment Control Block
SCO Santa Cruz Operations
SCSI Small Computer System
Interface
SCSI-SE SCSI-Single Ended
SDLC Synchronous Data Link
Control
SDR System Data Repository
SDRAM Synchronous Dynamic
Random Access Memory
SE Single Ended
SEPBU Scalable Electrical Power
Base Unit
SGI Silicon Graphics Incorporated
SGID Set Group ID
SHLAP Shared Library Assistant
Process
SID Segment ID
SIT Simple Internet Transition
SKIP Simple Key Management for
IP
SLB Segment Lookaside Buffer
SLIH Second Level Interrupt
Handler
SLIP Serial Line Internet Protocol
SLR1 Single-Channel Linear
Recording 1
SM Session Management
SMB Server Message Block
SMIT System Management
Interface Tool
SMP Symmetric Multiprocessor
SMS System Management
Services
SNG Secured Network Gateway
SOI Silicon-on-Insulator
SP IBM RS/6000 Scalable
POWER parallel Systems
SPCN System Power Control
Network
SPEC System Performance
Evaluation Cooperative
SPI Security Parameter Index
SPM System Performance
Measurement
SPOT Shared Product Object Tree
SPS SP Switch
SPS-8 Eight-Port SP Switch
SRC System Resource Controller
SRN Service Request Number
SSA Serial Storage Architecture
SSC System Support Controller
SSL Secure Socket Layer
468 IBM ^ Certification Study Guide - pSeries AIX System Administration
STFDU Store Float Double with
Update
STP Shielded Twisted Pair
SUID Set User ID
SUP Software Update Protocol
SVC Switch Virtual Circuit
SVC Supervisor or System Call
SWVPD Software Vital Product Data
SYNC Synchronization
TCE Translate Control Entry
Tcl Tool Command Language
TCP/IP Transmission Control
Protocol/Internet Protocol
TCQ Tagged Command Queuing
TGT Ticket Granting Ticket
TLB Translation Lookaside Buffer
TOS Type Of Ser vice
TPC Transaction Processing
Council
TPP Toward Peak Performance
TSE Text Search Engine
TTL Time To Live
UCS Universal Coded Character
Set
UDB EEE Universal Database and
Enterprise Extended Edition
UDI Uniform Device Interface
UIL User Interface Language
ULS Universal Language Support
UP Uniprocessor
USB Universal Serial Bus
USLA User-Space Loader Assistant
UTF UCS Transformation Format
UTM Uniform Transfer Model
UTP Unshielded Twisted Pair
UUCP UNIX-to-UNIX
Communication Protocol
VESA Video Electronics Standards
Association
VFB Virtual Frame Buffer
VG Volume Group
VGDA Volume Group Descriptor
Area
VGSA Volume Group Status Area
VHDCI Very High Density Cable
Interconnect
VLAN Virtual Local Area Network
VMM Virtual Memory Manager
VP Virtual Processor
VPD Vital Product Data
VPN Virtual Private Network
VSD Virtual Shared Disk
VT Visualization Tool
WAN Wide Area Network
WLM Workload Manager
WTE Web Traffic Express
XCOFF Extended Common Object
File Format
XIE X Image Extension
XIM X Input Method
XKB X Keyboard Extension
XLF XL Fortran
XOM X Output Method
XPM X Pixmap
XSSO Open Single Sign-on Service
XTF Extended Distance Feature
XVFB X Virtual Frame Buffer
© Copyright IBM Corp. 2001 469
Index
Symbols
$HOME/.netrc 294
maximum size 295
$HOME/.rhosts 295
./bosinst.data 220
./image.data 220
.bff file 99
.info file 99
.toc file 100
/etc/exclude.rootvg 221
/etc/hosts.equiv 295
/etc/inetd.conf 264
/etc/inittab
system resource controller (SRC) 246
/etc/locks/lpd 262
/etc/nologin 382
/etc/passwd 365
/etc/qconfig 399, 400, 412
/etc/qconfig example 399
/etc/rc.tcpip 262
/etc/resolv.conf 278
/etc/services 266
/etc/syslog.conf 250, 279
/etc/tcp.clean 262
/usr/lib/X11/fs/config 450
/var/adm/cron/cron.allow 255
/var/adm/cron/cron.deny 255
/var/spool/lpd/qdir 412
Numerics
64-bit Kernel 81
A
accessing
for system recovery 28
root volume group 30
root volume group, choices 32
activating
paging space 202
adding
alias 425
new user account 371
paging space 202
physical volumes, volume group 147
volume groups 145
volume groups, requirements 146
alias 424
building database 426
creating 425
delete 291
mail 424
multiple IP addresses 291
allocating
physical partitions 138
setting permissions on a physical volume 132
alog command 12, 14
entry in rc.boot 15
alternate disk installation 107
filesets required 107
anonymous FTP 297
applying
new maintenance level 108
software updates 95
at 253
attributes
Gecos 365
Shell 365
AutoFS 317
automount command 318
automountd 317
automatic mounts
unmounting 321
B
backup 216, 226
block size determination 236
-i option 228
incremental 228
online backup, alt_disk_install 108
backup file format 99
base device configuration 13
base operating system (BOS)
network file system installation 305
performance tools 336
Basic Networking Utilities 429
470 IBM ^ Certification Study Guide - pSeries AIX System Administration
batch 253
battery 49
bffcreate
creating bff files 106
binding
network file system (NFS) 312
boot
accessing a system 28
hard disk, diskless, service 12
boot disk
determining 34
boot image 13
damaged 33
recreating 33
boot list
changing 23
device naming 23
types 22
viewing 23
boot log file
alog syntax to view 17
contents 17
maintaining 15
boot logical volume
migrating 141
boot logical volume (BLV) 28
boot parameters service
network file system 304
boot process
cfgmgr flags used 19
description 12
phase-1 19
phase-2 19
resources 12
sequence, steps 19
types 12
understanding, phases/steps 13
boot up
alternate disk 108
bootable image
creating 210
bootlist command 12, 22, 141
BOS, installation 76
bosboot command 33, 141
C
cancel 405
CDE
disabling 384
enabling 384
cfgmgr 45, 280
phases of configuration 45
cfgmgr command 12, 18, 45
automatic configuration 20
rules, items 19
CGI-compliant Web server, online documentation
438, 440
changing
activation characteristics, volume groups 147
security attributes of user 379
service information 25
shell prompt 383
user attributes 374
user login shell 382
user password 372
chps command 201
chsec command 379
chsh command 382
chtz 254
chuser command 374
chvg command 147
Classical RISC/6000
boot signals 14
client server
network file system 304
clients, online documentation 437, 441
cloning
alternate disk rootvg 108
using a mksysb tape 237
commands
/etc/tcp/clean 262
/usr/lib/smdemon.cleanu 258
/usr/lib/spell/compress 257
alog 12, 14
at 253
automount 318, 322
backup 216
batch 253
bootlist 12, 22, 141
bosboot 33, 141, 210
cfgmgr 12, 18, 45, 280
chnfs 322
chnfsexp 322
chnfsmnt 322
chsec 379
chsh 382
chtz 254
Index 471
chuser 374
chvg 147
cpio 215
crontab 253
dd 35, 215
diag 61, 280
docsearch 441, 443
dtconfig 384
enq 390, 404
errclear 61
errdemon 54
errinstall 61
errpt 55
errupdate 61
exportfs 307, 322
extendvg 147
find 257
fixdist 98
fsck 34
getlvcb 125
hostname 299
ifconfig 291
init 246, 248
installp 86
instfix 100
inutoc 100
iostat 336
kill 252, 265
last 12, 20
lp 390
lpq 401
lpr 390, 401, 404
lpstat 401, 402, 404
lsattr 40, 50, 209, 336
lsdev 40, 280
lslpp 96
lslv 336
lsnfsexp 322
lsnfsmnt 322
lspv 40, 43, 134
lssrc 265, 279
lsuser 376
mail 430
mailq 432
mailstats 423
migratepv 141
mkboot 141
mkdev 70
mkitab 246
mknfs 306, 322
mknfsexp 322
mknfsmnt 322
mksysb 215, 219, 221
mkszfile 220
mkuser 371
mkvg 145
mount 312
mpcfg 12, 24
netstat 336
newaliases 426
nfso 322
nfsstat 336
nice 336
no 284, 336
odmadd 119
odmchange 119
odmcreate 119
odmdelete 119
odmdrop 119
odmget 119
odmshow 119
oslevel 83
passwd 372
pax 215
piobe 390
ps 336
qcan 405
qchk 401, 403, 404, 405
qdaemon 390, 391
qprt 390
reducevg 142, 148
refresh 252, 253, 265
renice 336
reorgvg 336
restore 216, 232
restvg 216
rm, skulker 257
rmdev 71, 142
rmfs 237
rmnfs 322
rmnfsexp 322
rmnfsmnt 322
rmuser 378
route 285
sar 336
savevg 215, 226
securetcpip 297
sendmail 417
472 IBM ^ Certification Study Guide - pSeries AIX System Administration
showmount 309
shutdown 12, 26
skulker 257
smdemon.cleanu 432
startsrc 246, 248, 262, 390, 451
stopsrc 262, 267
swapoff 205
swapon 211
sysdumpdev 210
syslogd 63
tar 215
tcopy 236, 239
tctl 216, 229, 230
telinit 246
time 336
trace 336
traceroute 285
umount 321
uname 299
uptime 12
vmstat 336
w 24
who 368, 381
wsm 442
xargs 257
xfsconf 451
committing
installed software 93
Common Desktop Environment 384
communications configuration
ODM system data 117
communications I/O
performance 334
compiling alias database 425
components, Documentation Search Service 437,
443
comsat 265
Configuration Assistant 81
configuring
database for 50
devices 45
Documentation Search Service 441
physical volumes 130
control block
logical volume 124
controlling
shutdown
adding applications to 27
corrupted
file system, recovering 34
JFS log, recovering 34
super block, recovering 35
cpio 215, 226
-i option 232, 235
-o option 228
CPU bound 350
creating
bff files 106
installation images, hard disk 106
JFS log 34
new physical volumes 132
user password 372
volume groups, mkvg command 145
volume groups, SMIT 145
cron 253
/var/adm/cron/log 254
/var/adm/cron/queuedefs 254
/var/spool/cron/crontabs/root 257
changes 254
restart 254
timezone (TZ) environment variable changed
254
xargs 257
crontab 253
/usr/lib/smdemon.cleanu 258
/usr/lib/spell/compress 257
/var/spool/mqueue/log 258
find 257
housekeeping 256
record format 254
rm, skulker 257
skulker 257
customized device database (CuDv)
ODM 119
D
daemon
comsat 265
cron 253
fingerd 265
ftpd 265
gated 262
inetd 262, 264
lpd 262
named 262
portmap 262, 268
refresh 253
Index 473
rexecd 265
rlogind 265
routed 262
rshd 265
rwhod 262
sendmail 262, 417
srcd 247
srcmstr 246
syslogd 250, 262, 279, 417, 422
talkd 265
telnetd 265
tftpd 265
timed 262
uucpd 265
database 50
ODM, logical volume 123
dd command 35, 215
duplicating disks 239
default mounts
network file system 314
DEFAULT_BROWSER, online documentation 442,
445
descriptors 118
desktop
installation 80
device configuration
ISA 49
ODM information 118
ODM system data 117
PCI 49
SCSI 49
devices 50
configuration database 50
configuring 20, 45
displaying information 50
listing 42
naming, bootlist command 23
removing, rmdev command 71
supported, listing 43
diag 61, 280
directory
mount point 312
dirty superblock 188
disabling
CDE 384
disk
quorum 125
Diskless Network Boot 13
displaying
fixes 100, 102
information about devices 50
installed filesets 96
installed fixes 100
logical volumes, rootvg 31
service information 24
user attributes 376
distributed file systems
network file system (NFS) 303
docsearch command 441, 443
document’s indexes, online documentation 438
documentation clients, online documentation 441
Documentation Search Service 437
components 437, 443
configuring 441
installing 440
Invoking 443
invoking 443
problem starting 444
Web based 437
documentation server, online documentation 442,
443, 445
DOMAIN protocol
/etc/resolv.conf 278
downloading
fixes 96
fixes using FixDist tool 98
dtconfig command 384
E
Editing
/etc/qconfig 402
enable 404
enabling
CDE 384
enq 405
enq command 390, 404
environment variable
DEFAULT_BROWSER 442, 445
HOME,LANG,PATH,TZ 369
shell prompt 383
errclear 61
errdemon 54
errinstall 61
errlogger 60
error codes
0503-005, invalid .toc file 107
0503-008, /tmp full 92
474 IBM ^ Certification Study Guide - pSeries AIX System Administration
0503-430, multiple installp running 89
error log
CHECKSTOP errors 33
system 54
errpt 55
errupdate 61
exp field
netstat 348
explicit mounts
NFS file systems 315
unmounting 321
exporting file systems
/etc/exports 307
network file system 304
NFS temporary export
exportfs -i 310
extending
/tmp file system 92
extendvg command 147
failing 147
F
failed installation
cleaning, installp command 90
failure
quorum problems 125
file systems
automatically mounting an NFS file system 317
changing NFS exported file systems 320
default remote file system 310
exporting NFS file systems 307
extending 92
journaled 123
mounting 35
mounting an NFS file system 311, 312
explicit mounts 315
NFS predefined mounts 313
unexporting an NFS file system 310
using a text editor 311
verifying 34
files
$HOME/.mailrc 432
$HOME/.netrc 294
maximum size 295
$HOME/.rhosts 295
$HOME/mbox 432
./bosinst.data 220
./image.data 220
/etc/aliases 424, 425, 433
/etc/aliases.dir 426
/etc/aliases.pag 426
/etc/bootparams 321
/etc/environment 369
/etc/exclude.rootvg 221
/etc/exports 307, 321
/etc/filesystems 311, 322
/etc/hosts.equiv 295
/etc/inetd.conf 264
/etc/inittab file 36
/etc/locks/lpd 262
/etc/motd 368
/etc/networks 322
/etc/passwd 364
/etc/pcnfsd.conf 322
/etc/preserve.list 79
/etc/rc.shutdown file 27
/etc/rc.tcpip 262, 419
/etc/resolv.conf 278
/etc/rpc 322
/etc/security/environ 360
/etc/security/failedlogin 368
/etc/security/lastlog 360
/etc/security/limits 361
/etc/security/login.cfg 367
/etc/security/passwd 366
/etc/security/user 362
/etc/sendmail.cf 423, 433
/etc/sendmail.cfDB 433
/etc/sendmail.nl 433
/etc/services 266
/etc/syslog.conf 250, 279
/etc/vfs 310
/etc/xtab 322
/usr/bin/Mail 432
/usr/bin/mail 432
/usr/bin/mailx 432
/usr/lib/security/mkuser.default 364
/usr/lib/smdemon.cleanu 433
/usr/sbin/mailstats 433
/usr/sbin/sendmail 432
/usr/sbin/shutdown script 27
/usr/sbin/skulker 257
/usr/sys/inst.images directory 106
/usr/ucb/newaliase 433
/var/adm/cron/log 254
/var/adm/cron/queuedefs 254
/var/adm/ras/bootlog file 15
Index 475
/var/adm/wtmp 368
/var/adm/wtmp file 20
/var/spool/cron/crontabs/root 257
/var/spool/mail 417, 432
/var/spool/mqueue 420, 432, 433
/var/spool/mqueue/log 258
/var/tmp/sendmail.st 423, 433
bos.rte.security fileset 80
creating bff files 106
crontab 254
etc/utmp 368
required for alternate disk installation 107
fileset
displaying 96
NetQ, online documentation 440
online manuals 443
Web browser 439
Web browser, online documentation 440
find, skulker 257
finding operating system version 83
fingerd 265
fixdist command 98
FixDist tool 96, 98
downloading fixes 98
using 98
fixed disks
performance 334
fixes
displaying 102
downloading 96, 98
ftp servers 98
level, understanding 83
fixpack, installing 96
forms-capable browser, online documentation 438
fragment size
JFS 123
fsck command 34
FTP
anonymous 297
logging 298
ftp 267
$HOME/.netrc 294
macro 294
maximum size 295
permissions 294
automatic login 294
ftp servers, fix downloading 98
ftpd 265
G
gated 262
gateway 285
netstat 348
Gecos attribute 365
getlvcb command 125
group of subsystems 248
groups
netstat 348
H
HACMP 240
hangup (HUP) signal 252
hard disk
boot 12
creating installation images 106
hd6 paging space 198, 200
moving 211, 212
reducing 209
host name resolution 277
/etc/resolv.conf 278
/etc/resolv.conf related problems 279
syslogd 279
hostname 299
housekeeping 256
I
identifying
physical volumes (PVID) 131
idle time
calculating 351
ifconfig 291
indexes, online documentation 438
inetd 262, 264
comsat 265
fingerd 265
ftpd 265
refreshing 264
rexecd 265
rlogind 265
rshd 265
starting 264
stopping 267
subservers 265
talkd 265
telnetd 265
tftpd 265
uucpd 265
476 IBM ^ Certification Study Guide - pSeries AIX System Administration
init 246
network 262
installation
64-bit Kernel and JFS2 81
alternate disk 107
Configuration Assistant 81
desktop 80
installation package set 80
Trusted Computing Base(TCB) 80
installation assistant 81
setting system defaults 82
installation images
saving on disk 106
installation package set 80
installing
alternate mksysb 110
automatic, prerequisites 92
base operating system (BOS) 76
Documentation Search Service 440
failed, installp command 90
failing, /tmp full 92
files for alternate disk installation 107
fixpack 96
images, creating on hard disk 106
individual fixes 103
migration install 79
migration, preserver, overwrite 78
new and complete overwrite 78
new machine 78
online manuals 442
optional software 86, 87
preview 92
service updates 86
Web browser, online documentation 439
Web server, online documentation 440
installp command 86
errors
0503-008, /tmp full 92
0503-430, multiple installp running 89
instfix command 100
interface
netstat 348
inutoc command 100
invalid boot list
recovering 34
invalid TOC 107
invoking, Documentation Search Service 443
iostat 336, 341
report output 343
IP forwarding
no 284
J
JFS2 81
journaled file system (JFS) 123
K
kernel init phase 13
kill 252, 265
L
last command 12
/var/adm/wtmp 20
finding shutdowns 21
syntax, flags 20
LED
201, damaged boot image 33
223-229, invalid boot list 34
551, corrupted file system 34
552, corrupted super block 35
553, corrupted /etc/inittab file 36
554 (see LED 552) 35
555 (see LED 551) 34
556 (see LED 552) 35
557 (see LED 551) 34
c31 29
power on 14
problems 33
listing
allocation
physical partition 138
available devices 42
characteristics, physical volumes 134
current maintenance level 96
devices
customized ODM 42
devices, predefined in ODM 41
information about physical volume 134
logical volume allocations 136
physical partition allocations 136
software, installp command 90
supported devices 43
Local Printer 390
logical partitions 122
logical volume 122
boot, migrating 141
Index 477
configuration data 123
control block 124
manager 123
mirroring 122
ODM database contents 123
paging 198
storage concepts 122
logical volume manager 123
login, last command 21
logout, last command 21
logs
JFS log, recreating 34
maintaining, managing 14
lp command 390
lpd 262
lpq command 401
lpr command 390, 401, 404
lprm 405
lpstat command 401, 402, 404
lsattr 336
lsattr command 40, 50
lsdev 40, 280
lsdev command 40
lslpp command 96
lslv 336
lsps command 201
lspv 40, 43
lspv command 40, 43, 134
lssrc 265, 279
lsuser command 376
M
mail 416, 417
addressing 428
local 428
network 428
aliases 424
/etc/aliases.dir 426
/etc/aliases.pag 426
building database 426
create 425
commands
mail 430
mailq 420, 432
mailstats 423, 432
newaliases 426, 432
sendmail 417, 426, 432
smdemon.cleanu 432
daemons 417
sendmail 417
syslogd 417, 422
logs 422
files 422
mailer information 423
mailer statistics 423
overview 416
queue 420
files 420
moving 421
printing 420
processing interval 419
storing 430
folders 430
personal mailbox 430
system mailbox 430
mail facility 415
mailers 416
bellmail 417
BNU 417, 429
SMTP 417
TCP/IP 417
UUCP 417, 429
routing program 416
user interface 416
maintaining
optional software, updates 95
maintenance level 75, 82
listing 96
software products 83
update all 103
updating 96
managing
logical volumes, LVM 123
physical volume 130
volume groups 143
managing logs
alog command 14
memory bound 350
message of the day file 368
migratepv command 141
migrating
boot logical volume 141
physical volumes 138
physical volumes, migratepv 141
physical volumes, SMIT 141
migration install 78
mkboot command 141
478 IBM ^ Certification Study Guide - pSeries AIX System Administration
mkdev command 70
mkitab 246
mkps command 201
mksysb 184, 215
alternate install 110
command 219
creating 221
-e option 221
excluding file system 221
tape image 219
tape layout 220
mkszfile 220
mkuser command 371
mkvg command 145
modification level
understanding 83
modifying
physical volumes 132
volume groups 146
mount
automatic mounts 317
default mounts 314
explicit mounts 315
mount point
explicit mount 316
NFS file systems 312
predefined mounts
/etc/filesystems 311
mount service
network file system 304
mounting file systems
network file systems (NFS) 304
moving
hd6 paging space 211
physical partitions 143
mpcfg command 12, 24
N
named 262, 279
netmask 280
netmasks
netstat 348
netstat 336, 345
fields
exp 348
gateway 348
groups 348
interface 348
netmasks 348
PMTU 348
refs 348
use 348
report output 346
network
init 262
problem, other consideration
file system full 300
file system not mounted 300
paging space full 300
server down 300
system resource controller (SRC) 262
network file system (NFS) 303
network information service (NIS) 317
new and complete overwrite install 78
new and complete overwrite installation 78
NFS
/etc/exports file 307
changing exported file systems 320
using a text editor 321
using smitty chnfsexp 320
default remote file system 310
/etc/vfs file 310
exporting file systems 304, 307
temporarily 310
using smitty mknfsexp 308
verify exports using showmount 309
mknfs command 306
mount point 316
mounting file systems 304, 311
/etc/filesystems 311
automatic mounts 312, 317
explicit mounts 311, 315
predefined mounts 311, 313
using smitty mknfsmnt 313
mounting process 312
automatic mounts 312
default mounts 314
predefined mounts 313
network information service (NIS) 317
NFS client
administration 319
NFS commands 321
automount 322
chnfs 322
chnfsexp 322
chnfsmnt 322
exportfs 322
Index 479
lsnfsexp 322
lsnfsmnt 322
mknfs 322
mknfsexp 322
mknfsmnt 322
nfso 322
rmnfs 322
rmnfsexp 322
rmnfsmnt 322
NFS daemons 321
/usr/bin/rpcgen 323
/usr/bin/rpcinfo 323
/usr/bin/showmount 323
/usr/sbin/biod 312, 323
/usr/sbin/nfsd 312, 323
/usr/sbin/nfsstat 323
/usr/sbin/portmap 323
/usr/sbin/rpc.lockd 322
/usr/sbin/rpc.mountd 312, 323
/usr/sbin/rpc.pcnfsd 323
/usr/sbin/rpc.statd 322, 323
automountd daemon 317
current status 319
starting NFS daemons 306
NFS files 321
/etc/bootparams 321
/etc/exports 307, 321
/etc/filesystems 311, 322
/etc/networks 322
/etc/pcnfsd.conf 322
/etc/rpc 322
/etc/xtab 322
NFS server 305
administration 319
NFS services 304
NFS transaction 305
planning, installation, and configuration 305
problem determination 323
bad sendreply error 326
checking network connections 325
checklist 323
hard-mounted file system problems 326
remote mount errors 327
server not responding 326
soft-mounted file system problems 326
remote procedure call (RPC) 303
starting NFS daemons using SRC 306
unexporting a file system 310
using a text editor 311
unmounting an automatic mount 321
unmounting an explicit mount 321
NFS client 304
administration 319
NFS explicit mounts 315
NFS mounting process 312
/etc/rc.nfs 312
/usr/sbin/nfsd daemons 312
binding 312
file handle 312
NFS server 305
administration 319
NFS services 304
boot parameters service 304
mount service 304
PC authentication service 304
remote execution service 304
remote file access 304
NFS transaction 305
nfsstat 336
nice 336, 349
no 284, 336
normal boot list 22
O
object class 118
descriptors 118
Object Data Manager (ODM) 117
ODM
basic components
object classes 118
objects 118
Customized Device Database (CuDv) 119
device configuration information 118
object 118
object class 118
descriptors 118
primary functions 117
system data 117
communications configuration information
117
device configuration information 117
SMIT menus, selectors, and dialogs 117
system resource information 117
vital product data, installation and update
117
ODM commands 118
odmadd 119
480 IBM ^ Certification Study Guide - pSeries AIX System Administration
odmchange 119
odmcreate 119
odmdelete 119
odmdrop 119
odmget 119
odmshow 119
ODM database
logical volume data 123
ODM databases 118
customized device database (CuDv) 119
ODM facilities 118
ODM object 118
online
backup 108
online HTML documents 437
optional software
installing 86
oslevel command 83
overwriting existing information
see new and complete overwrite 78
P
paging rate
calculating 352
paging space
adding and activating 202
characteristics 202
commands
chps 201
lsps 201
migratepv 212
mkps 201
rmps 201
swapoff 201
swapon 201
sysdumpdev 207
considerations 198
limitation 200
overview 198
performance 198
placement and sizes 200
removing 207
passwd command 372
pax command 215
PC authentication service
network file systems 304
PCI from Micro Channel cloning 237
PCI systems
boot signals 14
performance analysis 350
CPU bound systems 350
memory bound 350
physical partition
listing allocation 136
listing allocations 138
moving 143
physical partitions 122
physical volume 122
adding to, volume group 147
configuration 130
identity (PVID) 131
listing characteristics 134
listing information 134
listing, logical volume allocation 136
making disks 132
managing 130
migrating 138
removing 133
removing from 148
setting allocation permissions 132
setting availability 133
physical volumes
modifying 132
piobe command 390
PMTU
netstat 348
portmap 262
port number 268
remote procedure call (RPC) 268
starting 268
power on LEDs 14
predefined mounts
network file systems 313
prerequisites
automatically installing 92
refresh, subsystem 253
preservation install 78
installation
preservation 79
preserving
/var file system
/etc/preserve.list file 79
rootvg 79
user data 79
preview
fix information 105
software installation 92
Index 481
previous boot device 22
primary dump device 210
print job 389
print spooler 390
printer backend 391
functions 391
printer trouble shooting tips 411
problem determination
NFS 323
bad sendreply error 326
checking network connections 325
checklist 323
hard-mounted file system problems 326
remote mount errors 327
server not responding 326
soft-mounted file system problems 326
problem starting, Documentation Search Service
444
products
software, removing 94
ps 336, 382
Q
qcan command 405
qchk command 401, 403, 404, 405
qdaemon 246, 390
qdaemon command 390, 391
qprt command 390
queue 389
queue device 389
quorum 125
number of copies 125
problems 126
turning off 126
R
rc.boot script 15
redirecting output, alog command 15
read only storage 13
real memory
performance 334
real printer 390
recovering
corrupted /etc/inittab file 36
corrupted CuDv database 35
corrupted file system 34
corrupted JFS log 34
corrupted super block 35
damaged boot image 33
installp failure 90
invalid boot list 34
JFS log 34
system configuration 35
Redbooks Web site 454
Contact us 22
reducevg command 142, 148
reducing
paging space 209
physical volumes, reducevg command 142
refresh
daemon 253
group of subsystems 253
prerequisites, subsystem 253
subsystem 253
syslogd 252
refreshing
inetd 264
sendmail daemon 418, 419
refs
netstat 348
rejecting
software updates 93
updates 89
release number
understanding 83
remote execution service
network file systems 304
remote file access
network file systems 304
remote printer 390
remote procedure call (RPC) 268
network file system 303
removing
devices, rmdev command 71
disks from volume groups 142
paging space 207
physical volume 133
physical volumes 148
physical volumes, rmdev 142
saved files, committing software 93
software products 94
updates 90
user account 378
renice 336, 349
reorgvg 336
reports
iostat output 343
482 IBM ^ Certification Study Guide - pSeries AIX System Administration
netstat output 346
vmstat output 340
requirements
minimum space for, volume groups 146
resources
boot process 12
restart
cron 254
system resource controller (SRC) 247
restore 216, 232
-T option 231, 233
-x option 232, 233, 234, 236
restvg 184
restvg command 216
rexec
$HOME/.netrc 294
maximum size 295
permissions 294
automatic login 294
rexecd 265
rlogind 265
rmdev command 71, 142
rmfs 181, 237
rmps command 201
rmuser command 378
rootvg
preserving 79
route 285
routed 262
rshd 265
running
preview option for viewing 105
running threads
performance 334
rwhod 262
S
sar 336
savevg 226
-i option 226
savevg command 215
saving
installation images, /usr/sys/inst.images directo-
ry 106
saving ODM database 35
schedtune 336
scheduled commands 254
search engine, online documentation 440
search results page, online Documentation 437
securetcpip 297
sendmail 262, 416, 419, 420
daemon 417
qpi variable 419
queue processing interval 419
sendmail daemon
autostart, refreshing, status 419
starting 418
servers
network file systems 304
service boot 13
service boot list 22
service information
changing 25
managing, mpcfg command 24
saving 25
service updates
installing 86
setting system defaults
installation assistant 82
settings
TERM variable 70
Shell attribute 365
shutdown command 12, 26
adding applications to 27
signal
hangup (HUP) 252
size, paging space 200
skulker 257
/usr/sbin/skulker 257
SMIT
ODM system data 117
update /etc/inetd.conf 264
SMIT fast path
smit chinet 283
smit inet 281
smit mkroute 285
smit mktcpip 286
smit route 285
smit tcpip 281
smitty alt_clone 109
smitty alt_install 108
smitty assist 82
smitty bffcreate 106
smitty install_commit 93
smitty install_latest 91
smitty install_reject 93
smitty install_remove 94
Index 483
smitty install_update 90
smitty instfix 103
smitty migratepv 141
smitty mkps 203
smitty mkvg 145
smitty show_apar_stat 102
smitty update_all 103
smitty update_by_fix 103
smitty vgsc 147
SMS 49
software
applying 88
cleaning up failed installation 90
committing 88
committing applied filesets 89
finding out, level 83
installing 87
listing, installp command 90
maintenance level, products 83
on media, listing 90
packaging 84
rejecting 89
rejecting updates 93
removing 90
removing copies 93
removing products 94
srcd 247
starting
group of subsystems 248
inetd 264
portmap 268
sendmail daemon 418
subserver 248
subsystem 248
syslogd 250
system resource controller (SRC) 246
TCP/IP 262
startsrc 246, 248, 262, 390
flags 248
xfs 451
status
VGSA 124
stopping
inetd 267
sendmail daemon 418, 419
TCP/IP daemons 262
stopsrc 262, 267
storage
logical volume, concepts 122
subservers 245, 265
comsat 265
fingerd 265
ftpd 265
inetd 265
lssrc 265
rexecd 265
rlogind 265
rshd 265
starting 248
talkd 265
telnetd 265
tftpd 265
uucpd 265
subsystem 245, 248
qdaemon 246
superblock
dirty 188
svmon 336
swap space 198
swapoff 205
swapoff command 201
swapon command 201
syslogd 63, 250, 262, 279
collecting data from multiple systems 252
configuration file 250
daemon 62
ODM stanza 250
refresh 252
starting 67, 250
system boot phase 13
system configuration
copying 35
system data 117
system dump device
displaying, changing 207
system dynamics
communications I/O 334
fixed disks 334
performance 334
real memory 334
running threads 334
system error log 54
description 54
System Management Services
see SMS 49
system performance 333
BOS tools 336
classes of workload 335
484 IBM ^ Certification Study Guide - pSeries AIX System Administration
multiuser 335
server 335
workstation 335
commands
iostat 336, 341
lsattr 336
lslv 336
netstat 336, 345
nfsstat 336
nice 336
no 336
ps 336
renice 336
reorgvg 336
sar 336
time 336
trace 336
vmstat 336
determining CPU bound systems 350
determining memory bound systems 350
idle time 351
overview 336
paging rate 352
performance analysis 350
CPU bound 350
memory bound 350
reports
iostat output 343
netstat output 346
vmstat output 340
system dynamics 334
communications I/O 334
fixed disks 334
real memory 334
running threads 334
system resource controller (SRC)
/etc/inittab 246
init 246, 248
mkitab 246
network 262
NFS daemons 306
restart 247
srcmstr 246
starting 246
startsrc 246, 248, 390
subserver 245
subsystem 245
telinit 246
update /etc/inetd.conf 264
system resource information
ODM system data 117
T
table of contents
.toc file 100
error, 0503-005 107
updating, creating 100
talkd 265
tar 215, 226
-c option 227
-x option 232, 235
target words, online documentation 437
tcopy 236
duplicating tapes 239
TCP/IP
$HOME/.netrc 294
maximum size 295
permissions 294
alias
delete 291
multiple IP addresses 291
boot without starting 263
ftp 264
ping 264
telnet 264
change IP address 286
ftp 267
gated 262
gateway 285
host name resolution 277
hostname 299
ifconfig 291
inetd 262, 264
IP forwarding 284
lock files 262
lpd 262
named 262
netmask 280
network interface 264
no 284
portmap 268
portmapd 262
route 285
routed 262
rwhod 262
sendmail 262
starting 262
Index 485
startsrc 262
stopsrc 262
telnet 267
timed 262
traceroute 285
uname 299
tctl 229, 232, 233, 234
rewind tape 230
tctl command 216
telinit 246, 247
telnet 267
telnetd 265
TERM environment variable 70
tftpd 265
time 336
timed 262
topas 198
tprof 336
trace 336
traceroute 285
troubleshooting
accessing down system 28
corrupted /etc/inittab file 36
corrupted file system 34
corrupted JFS log 34
corrupted super block 35
damaged boot image 33
invalid boot list 34
Trusted Computing Base (TCB) 80
turning off
quorum 126
U
uname 299
understanding
fix level 83
modification level 83
release numbers 83
UNIX-to-UNIX Copy Program 417, 429
unlocking
volume group 147
update
applying 95
committing 89
definition 95
maintenance level 96, 103
rejecting 89
rejecting updates 93
removing 90
software, applying fixes 83
upgrade 79
uptime command 12, 23
use
netstat 348
user administration commands 359
uucpd 265
V
verifying
file systems 34
verifying software
preview option 92
version
meaning 83
operating system, oslevel command 83
vital products
ODM system data 117
vmstat 198, 336
report output 340
volume group 122
adding 145
adding, physical volumes 147
descriptor area, VGDA 123, 124
information 31
managing 143
modifying 146
removing, physical volumes 148
status area, VGSA 124
unlocking 147
W
w command 24
Web browser, online documentation 437, 439, 441,
444
Web server, online documentation 437, 440, 442,
445
who command 381
workload
performance 335
multiuser 335
server 335
workstation 335
Workload Manager 350
wsm command 442
(1.0” spine)
0.875”<->1.498”
460 <-> 788 pages
IBM ^ Certification Study Guide -
pSeries AIX System Administration
®
SG24-6191-00 ISBN 0738423777
INTERNATIONAL
TECHNICAL
SUPPORT
ORGANIZATION
BUILDING TECHNICAL
INFORMATION BASED ON
PRACTICAL EXPERIENCE
IBM Redbooks are developed by
the IBM International Technical
Support Organization. Experts
from IBM, Customers and
Partners from around the world
create timely technical
information based on realistic
scenarios. Specific
recommendations are provided
to help you implement IT
solutions more effectively in
your environment.
For more information:
ibm.com/redbooks
IBM
Certification Study Guide -
pSeries AIX System Administration
Developed
specifically for the
purpose of preparing
for AIX certification
Makes an excellent
companion to
classroom education
For AIX professionals
This redbook is designed as a study guide for professionals
wishing to prepare for the certification exam to achieve: IBM
^ Certified Specialist - pSeries AIX System
Administration. The system administration certification
validates a broad scope of AIX administration skills and the
ability to perform general AIX software system maintenance.
This redbook helps AIX administrators seeking a
comprehensive and task-oriented guide for developing the
knowledge and skills required for the certification. It is
designed to provide a combination of theory and practical
experience needed for a general understanding of the subject
matter. It also provides sample questions that will help in the
evaluation of personal progress and provide familiarity with
the types of questions that will be encountered in the exam.
This redbook does not replace practical experience you
should have, but is an effective tool that, when combined with
education activities and experience, should prove to be a very
useful preparation guide for the exam. Due to the practical
nature of the certification content, this publication can also be
used as a desk-side reference. So, whether you are planning
to take the pSeries AIX System Administration certification
exam, or if you just want to validate your AIX system
administration skills, this redbook is for you.
Back cover
