AIX V5.3 installation best practices

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Important note There is no substitute for hands-on training with an instructor to learn the basics before attempting the first AIX installation on a production system. See the IBM Training web page. In the US, see the IBM Training AIX 5L System Administrators web page to select a course.

This web page is meant to supplement, not replace, other documentation which has been published:

• How-To's for AIX Installation Tasks - System p and AIX information center article covering frequently-used AIX installation procedures.
• Installing AIX in a partitioned environment - System p and AIX information center article focussing specifically on installing AIX in an LPAR. Includes sections on setting up a Network Installation Management (NIM) server from which individual LPARs can be installed over the network. No need to find or shuffle CDs! Once NIM is configured, install AIX and optional components in a single step - fire and forget!
• Software installation and maintenance - System p and AIX information center article describing how to perform various tasks related to AIX installation and maintenance.
• How to install AIX 5L - IBM developerWorks article with step-by-step instructions for a number of generic AIX system setup procedures which should (with minor exceptions) work for any of the AIX 5L releases.
• Installing optional software products or service updates - System p and AIX information center article describing how to install additional software once the AIX base installation is done.
• IBM eServer Certification Study Guide - pSeries AIX System Administration - An excellent reference source for AIX sysadmins. Chapters are:
  1. Certification overview
  2. System startup problem handling
  3. Hardware assistance
  4. System and software installation
  5. Object Data Manager
  6. Storage management, LVM, and file systems
  7. System paging space
  8. System backup, restores, and availability
  9. System Resource Controller administration
  10. Network administration
  11. Network File System administration
  12. System performance
  13. User administration
  14. Printing
  15. Sendmail and e-mail
  16. Online documentation
  17. The AIXwindows font server
• AIX V5.3 Installation Tips - Published on IBM's Subscription service web site. (An IBM ID is required for access. Registering for an IBM ID is quick and easy.) IBM's Subscription service can deliver alerts via e-mail of (among other things) new installation tips as they are published and AIX defects for which fixes have recently become available. Check periodically for new tips.

AIX V5.3 installation

Installing the base AIX operating system is very quick and easy. It is discussed thoroughly in the above reference sources. At the end of the AIX base installation process, follow the prompts in the AIX installation assistant to:

• set the system date, time, and time zone,
• set the root password,
• bring the system up on the network, and
• install additional software (see below).

Note According to the Viewing BOS installation logs article, the activities which occur during base AIX installation are recorded in /var/adm/ras/bosinst.log file (which can be viewed with any text editor) and in /var/adm/ras/bosinstlog (which can be viewed with alog -t bosinst -o).

Note You can access the AIX installation assistant after exiting from it (even after specifying that the installation assistant is not to be started at boot time) by issuing the command install_assist (when using X-Windows) or smitty assist (when using an ASCII terminal). install_assist may not work properly once a new Technology Level is installed on base AIX. If, for example, AIX V5.3 is installed from media at the TL04 level and AIX is then updated to the TL05 level, the install_assist command will hang when invoked, as reported in IBM internal CMVC Defect 567207. Best to finish using install_assist before installing a TL. According to Moemen El Swedey, if install_assist hangs when invoked, the issue can be addressed by installing the AIX Security expert filesets (bos.aixpert.cmds and bos.aixpert.websm) and making sure that certain other filesets are at the following levels (or above): bos.sysmgt.serv_aid 5.3.0.51 bos.sysmgt.sysbr 5.3.0.40 sysmgt.websm.rte 5.3.0.40 sysmgt.websm.apps 5.3.0.40 sysmgt.websm.framework 5.3.0.40 (Use lslpp -l | grep sysmgt to check the levels of these filesets.) If the level of your AIX installation media is too old to have the AIX Security Expert filesets, they can be downloaded by following the link at the bottom of the Where to find aixpert entry in the AIX Forum on the IBM developerWorks web site.

When installing AIX V5.3 on a LUN on a Storage Area Network (that is, when preparing to boot AIX from SAN), please note that there are some special considerations.

In addition to the changes prompted by the AIX installation assistant, the following actions are recommended:

• before putting installation images in /usr/sys/inst.images, create a /usr/sys/inst.images filesystem and mount it,
• before tailoring the base AIX installation, consider saving a copy of /etc/rc, /etc/inittab, /etc/environment, /etc/passwd, /etc/group,
  /etc/security/limits, /etc/security/passwd, /etc/security/user, /etc/security/group, /etc/services, /etc/inetd.conf, /etc/netsvc.conf,
  /etc/motd, and /etc/filesystems,
• configure the root user so you always know which system you are on and which directory you are in,
• before creating any userids for which /bin/ksh is the default shell, update the /usr/lib/security/mkuser.sys file shipped with AIX,
• enlarge /tmp & /var filesystems (to 512 MB?),
• enlarge /home (to provide enough space for user's home directories),
• enlarge the default paging space and/or allocate additional paging spaces (smitty pgsp - see the Paging space and virtual memory article for advice),
• make a few changes to AIX kernel tuning parameters,
• make sure adequate system dump space is allocated,
• prepare the system so you can initiate a stand-alone dump if AIX hangs,
• update $MANPATH for all users,
• configure TCP/IP to search local /etc/hosts to resolve a host name before trying DNS,
• add useful shell scripts to /usr/local/bin and make them available to all users, and
• create a CD-ROM filesystem with a mount point of /cdrom.

Please note that important optional software components are not installed by when base AIX is installed from installation media. So, once base AIX has been installed, there is still software to be installed:

• Install the appropriate AIX bundles using the command smitty install_bundle. The Server and Mozilla bundles are the most popular bundles. Installing the Mozilla bundle requires access to the AIX Toolbox for Linux Applications and Mozilla CDs. Mozilla can be installed independently (without using the bundle). Other bundles (eg, App-Dev) are useful in some environments.
• Install a few individual filesets in addition to bundles.
• Install OpenSSH.
• Install Adobe Acrobat Reader.
• Install lsof (LiSt Open Files) utility.
• Consider installing packages from the AIX Toolbox for Linux Applications web site. (Please note that it is often possible to download from the Internet more current and useful versions of software for AIX than those available on the AIX Toolbox for Linux Applications web site.) Here are some examples of software available on the AIX Toolbox for Linux Applications web site:
  • VNC runs on AIX and creates an X-windows desktop which can be used from any web browser, including Internet Explorer. Very useful when installing applications such as Oracle which provide an X-windows-based installation GUI. More than one user can view and use the X-windows desktop simultaneously, so users can watch what another user does on the X-windows desktop, which is very useful when collaborating with others. Documentation is available, although the documentation might not correspond to the release delivered in the AIX Toolbox for Linux Applications.
  • sudo manages root access
  • VIM editor with improvements over vi
  • GNU Bourne Again shell (bash) which those familiar with Linux usually prefer. Hint: If AIX userids will be defined with bash as the login shell, consider tailoring /usr/lib/security/mkuser.sys to provide an appropriate default .bash_profile for those users.
  • Ethereal network problem analysis tool
  • wget tool to download web pages
  • Samba file and print server for Microsoft Windows clients
  • MySQL open source RDBMS
  • Apache web server (but the IBM HTTP Server might be a better choice)
  • GCC (GNU Compiler Collection)
• Create a bootable system backup using mksysb to preserve the work that has been done up to this point.
• Mirror the AIX rootvg. Remember that any new logical volumes or filesystems created in rootvg after this will not automatically be mirrored, so it's a good idea to postpone this step until near the end of the installation process. If oslevel -r reports that AIX is running at a very old Maintenance/Technology Level, it might be a good idea to proceed to the next step and install a recent Technology Level before attempting to mirror rootvg, which will address any known defects in the rootvg mirror process.

Once all desired filesets and bundles have been installed, select and install a Technology Level and Service Pack. Please note that if additional AIX filesets or bundles are installed after a Technology Level has been installed, it is important to reinstall the Technology Level. And please note that software updates for optional software products (the C and C++ compilers, HACMP, etc) are not included in a Technology Level, nor are updates for Java. Those components must be updated individually.

Last but not least Reboot (shutdown -Fr} AIX to confirm that the reboot runs cleanly and create another bootable backup to preserve the work that has been done.

Selecting an AIX Technology Level and a Service Pack

An AIX Technology Level is an update to AIX containing fixes and new hardware and software features. (AIX software updates are now bundled in Technology Levels rather than Maintenance Levels.) A new AIX Technology Level is released every six months. For more information regarding the AIX Technology Level concept (and a comparison of Technology Level concept with the Maintenance Level concept), see the IBM AIX 5L Operating System Service Strategy Details and Best Practices document downloadable from the Service and support best practices for UNIX servers web page.

To select and download an AIX Technology Level and a Service Pack, point a browser at the Fix packs for AIX 5.3 operating system web page, select All 5.3 in the Select a Technology Level select box, and click . ( To find Technology Levels and Service Packs for AIX releases other than V5.3, point a browser at the Fix Central home page, select System p in the Product family select box, select AIX in the Product select box, select the AIX version desired in the Version select box, elect Fix packs in the Fix type select box, and then click Continue.)

Select the latest AIX Technology Level and Service Pack, unless there is considerable urgency to put the server into production, in which case it may be prudent to avoid an AIX Technology Level (and Service Pack) during its first month or two of availability. Better to let another customer (who is not under as much time pressure) encounter problems with the Technology Level (or Service Pack) and resolve them. (AIX Technology Levels and Service Packs are thoroughly tested, but due to the enormously flexible nature of software nowadays, every permutation and combination can not possibly be tested. Even the most thoroughly tested software has a few problems still lurking in the weeds.) If there is urgency to get something into Production and the latest Technology Level (or Service Pack) has been out less than a month, fall back to the Technology Level (or Service Pack) prior to the latest one.

When selecting a Technology Level, consider the Technology Level's service life. The Fix packs for AIX 5.3 operating system web page says:

"Beginning with AIX 5300-06, Technology Levels are supported for approximately two years. End Of Support dates are estimates only. A two year life for a TL is an objective only. All statements regarding IBM's future direction and intent are subject to change or withdrawal without notice, and represent goals and objectives only."

In this context, "supported" means that the IBM Support Center will build a fix for a particular Technology Level for up to two years. If a problem is encountered in a Technology Level which is no longer supported, if a fix is not already available, and if a fix is required, the IBM Support Center will build a fix only on a supported Technology Level. In order to install the fix, it will be necessary to upgrade AIX to the Technology Level on which the fix is built. There is, therefore, motivation to avoid implementing a Technology Level which has been available for a long time, because the older a Technology Level, the less time remaining in it's service life.

Note In most cases, installing the latest Technology Level is the best choice, because the latest Technology Level has the longest remaining service life and, since Technology Levels are cumulative, because the latest Technology Level has fixes for the largest number of defects.

Minimum required AIX Technology Level

Be sure to select a Technology Level which will run on your server. The IBM Sales Manual has information on the minimum AIX maintenance level required for every System p server and I/O drawer. To access the IBM Sales Manual, point a browser at the IBM Offering Information web site and (on the A specific type tab) select Type of content:    HW & SW desc (Sales manual, RPQ).

To locate the entry for a specific machine type-model (eg, 9116-561) in the Sales Manual, click on the Advanced search link, type the machine type-model in the Product number: box, check the Hardware product descriptions & Entire date range boxes, and click the Search icon at the bottom of the window. Once you are viewing a Sales Manual entry, follow the Technical Description link, then the Software Requirements link to find the minimum AIX technology level required for the machine type-model.

If you are uncertain of the machine type-model for a server on which AIX is already running in your environment, issue the command prtconf | head and look for the System Model: field.

If a server has I/O drawers attached, you must also look at the Sales Manual entry for the I/O drawer and meet the minimum AIX technology level for the I/O drawer as well as for the server.