AIX Unix: IBM AIX help, commands and current versions

Updated November 2026

AIX is IBM's Unix for its Power servers. It is known for stability and strong virtualisation, and it runs core systems at many banks, insurers and manufacturers. Unlike most commercial Unix systems, it is still actively developed.

Versions and support

The current release is AIX 7.3. IBM ships new function in Technology Levels (TL); AIX 7.3 TL4 arrived in December 2025, adding support for larger LPARs and production use of Live Library Update. Each Technology Level gets about three years of fixes, released as Service Packs, so plan to move up a TL every year or two. AIX 7.2 is still supported at its final level, TL5; AIX 7.1 reached end of standard service in 2023. Check IBM's lifecycle pages for exact dates for your level.

What level am I running?

oslevel -s            # full level, e.g. 7300-04-01-2546
oslevel -r -l 7300-04 # filesets below the given technology level
prtconf | head -20    # machine type, processors, memory, firmware
lsattr -El sys0       # system attributes
instfix -i | grep ML  # are all filesets of each level installed?

Installing fixes

Download Technology Levels and Service Packs from IBM Fix Central, or let SUMA (Service Update Management Assistant) fetch them.
Install with smitty update_all or install_all_updates -d /path. Preview first with -p.
Interim fixes (iFixes) for security problems are managed with emgr: emgr -l lists them.
Before updating, clone the running system to a spare disk with alt_disk_copy -d hdisk1, so you can boot back if something fails. With multibos you can keep a standby boot environment on the same disks.

SMIT

SMIT (System Management Interface Tool) is a menu interface to almost every administration task. Run smitty for the text version. Press F6 on any screen to see the command it would run, a good way to learn the command line, and look in ~/smit.log and ~/smit.script for what you did.

Disks: LVM and JFS2

AIX has had a logical volume manager since AIX 3 in 1990. Physical volumes (hdisk) are grouped into volume groups, which contain logical volumes and JFS2 file systems.

lspv                        # disks and their volume groups
lsvg -o                     # active volume groups
lsvg -l datavg              # logical volumes in a group
lsvg datavg                 # free space in the group
chfs -a size=+10G /data     # grow a file system online
mklv -y datalv -t jfs2 datavg 20G
crfs -v jfs2 -d datalv -m /data2 -A yes
lsfs                        # file systems and their mount points
mirrorvg rootvg hdisk1      # mirror rootvg onto a second disk

Devices

lsdev -Cc disk              # configured disks
lsdev -Cc adapter           # adapters
lscfg -vl fcs0              # details of a Fibre Channel adapter, including WWPN
cfgmgr                      # detect new devices
errpt | head                # error log summary (check this first when something fails)
errpt -a -j IDENTIFIER      # full details of one error type

Performance

Tool	Shows
`topas`	Interactive overview of CPU, memory, disks, network and top processes
`nmon`	Interactive or recorded performance data (built into AIX); analyse with the nmon analyser
`vmstat 2 5`	CPU, memory and paging, five samples two seconds apart
`iostat -D 2`	Disk service times and queues
`svmon -G`	Memory use in detail
`lparstat 2`	Processor use of a shared-processor LPAR, including entitlement

Software packages

lslpp -l | grep -i ssh      # installed filesets (AIX's own packages)
lslpp -w /usr/bin/ssh       # which fileset owns a file
installp -acgXYd . bos.adt  # install a fileset from the current directory
dnf install git             # open-source software from the AIX Toolbox for Open Source

IBM's AIX Toolbox provides RPM packages of open-source tools (bash, git, Python, GNU utilities) with dnf.

Differences from Linux to watch for

Users: mkuser, chuser, lsuser, rmuser; attributes live in /etc/security/user and /etc/security/limits.
Services are controlled by the System Resource Controller: lssrc -a, startsrc -s sshd, stopsrc -s sshd, refresh -s syslogd.
The boot sequence uses /etc/inittab (edit with mkitab, chitab, lsitab); there is no systemd.
The default shell is the Korn shell (ksh), and many commands lack GNU options such as sed -i. Install the GNU versions from the Toolbox or write portable scripts.
Network settings are stored in the ODM: change them with chdev or smitty tcpip, not by editing files.

Clustering and virtualisation

Power servers are partitioned into LPARs, managed from the Hardware Management Console (HMC), with the Virtual I/O Server (VIOS) sharing disks and networks. For high availability, AIX uses IBM PowerHA SystemMirror (formerly HACMP); InfoScale (formerly Veritas InfoScale) is also available for AIX. See the Veritas cluster section.

Learn more

IBM AIX 7.3 documentation
IBM Redbooks: free, detailed books on AIX, PowerVM and PowerHA
AIX Toolbox for Open Source Software