AIX for the System Administrator

Glossary
Boot Process
Disks
Dump Space
Filesystems
Kernel
Networking
Paging and Swap Space
Password/Account Reset
Processes
Software Installation and Patches
System Information
System Monitoring
Tapeutil
Terminal Configuration
Troubleshooting --> see aix-troubleshooting.html
Users

Glossary

Term
 Definition
Advanced Interactive Executive (AIX)
 RS/6000 Unix Operating System
Authorized Program Analysis Report (APAR)
 Used to identify a fix for a PMR.
Base Operating System (BOS)
Fileset
Fragments Allows disk space to be divided into units that are smaller than the size of a logical block
High Availability Cluster Multiprocessor  ?? (HACMP)
 AIX Clustering
I-Node 128 bit structure that contains information about the file or directory such  as ownership, permissions, file type, number of links to the file, etc.
Logical Block Disk block that contains file or directory data
Maintenance Level (ML)
 Service updates necessary to upgrade the BOS to the current release level
ODN
Page
 4KB unit of virtual memory than can be transferred between physical ram and disk paging space
Paging Space
 Special logical volume used for holding inactive data that has been temporarily transferred out of physical ram.
Phsysical Volume ID (PVID)
 Unique id that consists of a hash of the CPUID and the date.
Problem Management Record (PMR)
 Tracking record used for customer problems.
Program Temporary Fix (PTF)
 Temporary fix that will be incorporated into the next release of the product.  May be a single fix or multiple fixes associated with a single fileset.
Service Boot
 Server is started with the key in the service position (as opposed to the key being in the normal position).
Superblock Disk block that contains information about the entire file system.  It starts at byte offset 4096 and is 4096 bytes in size.
Swap Space
 See Paging Space above.
System Management Interface Tool (SMIT) Menu driven system administration interface for AIX
Vpath
 Similar to HP LUN?


Boot Process

Phases of the Boot Process:
  1. Read Only Storage Kernel Init Phase
    1. Motherboard is Checked
    2. Bootlist is found
    3. Boot image is read into memory
    4. Initialization starts
  2. Base Device Configuration Phase
    1. All devices are configured with cfgmgr command
  3. System Boot Phase
    1. Logical volumes are varied on
    2. Paging is started
    3. /etc/inittab is processed
Commands

alog - allows the administrator to view logs
alog -L  <-- displays log files that alog can view
alog -o -t boot   <-- displays the boot log file
cfgmgr
last
bootlist
uptime
mpcfg
shutdown

How to boot the system if the Service Processor Firmware Menu is displayed:

Service Processor Firmware
         Main Menu

1.  Service Processor Setup Menu
2.  System Power Control Menu
3.  System Information Menu
4.  Language Selection
5.  Call In/Call Out
6.  Set System Name
99.  Exit Menu

Choose Option 2:  System Power Control menu, then select option to Power On

How to boot to the SMS Menu (to apply firmware updates)
Startup Scripts

Disks


lsdev -C -c disk  - shows available disks on the server

lsfs    <-- show the filesystems on the server and their characteristics

lspv  - shows disks and their LVM information or "none" if not part of LVM

dumpfs <disk> - shows superblock, i-node map and disk map information for the file system specified.

df -v - shows the number of i-nodes used and free.

istat - shows the last updated, last modified and last accessed times of a file.

ls -i - shows the i-node number assigned to a file

bosboot -a  --> creates a new bootimage

bootlist -m normal -o hdisk0 hdisk1  --> puts hdisk0 and hdisk1 on the bootlist

bootlist -m normal -o  --> displays the current bootlist

How to mount a cdrom

Dump Space

The system dump facility copies critical information to the dump device when a system crash occurs.  This information is critical for determing the cause of the crash.

sysdumpdev -l  <-- shows where the system dump location currently is located.

sysdumpdev -P -p /dev/hd9   <-- changes the primary dump device to hd9

sysdumpdev -e   <-- estimates the size of the current dump

smitty dump   <-- access dump configuration through smit

Procedure for manually peforming a system dump
Procedure to verify a system dump
Procedure to generate a system dump using snap

Filesystems

Additional information in the file aix-lvm.html.

 mount -t <type>  --> mounts all filesystems in /etc/filesystems containing the t=type attribute

Copying files

Argument list too long error

Kernel

Changing from 32 bit kernel to 64 bit kernel


Networking

entstat -d en0   <-- this will display configuration and statistics for the network card "en0" - useful for displaying speed/duplex configuration

Paging and Swap Space

Utilities to monitor paging space:
lsps -a  <- Lists paging space by disk
chps -s 16 hd6   <- Changes the paging space by adding 16 logical partitions to the hd6 logical volume (default swap space device)
chps -d 16 hd6  <- Changes the paging space by deleting 16 logical partitions from the hd6 logical volume
mkps  <--  Makes additional paging space
rmps  <--  Deletes paging space  (paging space must be deactivated by chps and then system must be rebooted to remove the paging space)
swapon  <-- Turns on a paging space
swapoff  <-- Turns off a paging space

Total Paging Space = 512MB + (Physical Memory Size - 256MB) * 1.25


Processes and Services

/etc/inetd.conf - inetd configuration file
/etc/services - information about services, such as port number

Starting and stopping a process:
refresh -p <pid>
refresh -s <subsystem name>

Changing the inetd configuration

Software Installation and Patches

lslpp -l "<fileset>"   <--  Shows information about filesets

rebuild .toc file - "inutoc"  <-- This rebuilds the toc where the bff's are located.  Needed if something is added to an existing fileset or new file will not be found.

root.oncwhst5:/# instfix -ciqk 5100-04_AIX_ML | grep ":-:"

root.oncwhst5:/# lslpp -l bos.iconv.ucs.com


Displaying the maintenance level and fixes that are installed

Procedure to upgrade the maintenance level of the os


System Information

prtconf|more  <-- prints system information (aix 5.x)
amount of ram - bootinfo -r or lsattr -El sys0 -a realmem
number of  processors - lscfg | grep proc or bindprocessor -q

oslevel  --> returns the major level of the OS (such as 5.0)
oslevel -r  -->  returns the detailed level of the OS, with sub level and patch level info (such as 5.1)
uname -a
uname -uM  --> type of machine and serial number

System Monitoring

topas = top on hp-ux

Tapeutil

To run the menu version type "tapeutil"

To manually use tapeutil
To manually remove a tape from the drive using tapeutil:


Terminal Configuration

Autocompletion:  <esc>\

Troubleshooting

See aix-troubleshooting.html

Users

Commands:
mkuser  -->  utility the creates a new user
passwd  -->  change the user's password
chuser  -->  change the user's attributes
chuser minother=# <user>  --> changes minother atttribute for a user
luser <user>    -->  lists the attributes for a specific user account
lsuser -f <user>  --> lists each attribute on it's own line
rmuser  -->  utility that removes a user
chsec  -->  change the user's security attributes
login 
who  -->  lists who is currently logged into the system
whoami (who am i)  --> displays information about yourself
dtconfig

Files:
/etc/security/environ  --> lists environment attributes for each user
/etc/security/lastlog  --> lists last login attributes for each user
/etc/security/limits   -->  lists process resource limits for each user
/etc/security/user  --> lists extended user attributes for  each user
/usr/lib/security/mkuser.default  --> lists default attributes for new users
/usr/lib/security/mkuser.sys  --> script that sets up the user's environment
/etc/passwd  --> lists basic user attributes for each user
/etc/security/passwd  -->  contains password information for each user
/etc/security/login.cfg  -->  lists login security information for each user
/etc/utmp  --> contains users that are logged into the system, used by the "who" command
/var/adm/wtmp  -->  contains connect time information for users
/etc/security/failedlogin  --> contains unsuccessful login attempts
/etc/motd  -->  message of the day that is displayed when the user logs in.
/etc/environment  --> lists the default environment that new processes will use.
/etc/profile  -->  environment settings for all  users
$HOME/.profile  -->  environment settings for a specific user
/etc/group  -->  lists attributes for each group
/etc/security/group  -->  lists extended attributes for each group

Important /etc/security/user attributes to know about:

account_locked   -->  true or false
expires -->  Expiration time for a user account.  MMDDHHMMYY,  a value of 0 indicates no expiration
loginretires  -->  Number of invalid login attempts before a users is not allowed to login.  A value of 0 indicates this attribute is disabled.
maxage  --> Maximum number of weeks a password is valid, a value of 0 indicates unlimited
minage  -->  Minimum nuimber of weeks between password changes.

Procedure to add a new user

Procedure to change the password on a server

passwd <User>

Note:  The account needs to be reset if when trying to log in the following message is received:

3004-303 There have been too many unsuccessful login attempts; please see
        the system administrator.

Procedure to reset the account:

1.  chsec -f /etc/security/lastlog -a "unsuccessful_login_count=0" -s N500620

2.  chuser "account_locked=false" N500620

Procedure to change the shell prompt: