AIX 5.x/6.1/7.1 Installation from scratch

Base system

From CD/DVD

Straightforward. Insert first CD/DVD and proceed. To override an existing system on the harddisk, press reset button and re-boot in maintenance mode, selected by during boot. Alternatively, on an already running system, one may use 
bootlist -m normal cd0
bootlist -m normal -o
shutdown -Fr
to start installation from CD.
When prompted, select En_US as language and the default keyboard. Depending on what you want, select Migration or Overwrite" installation.
Optionally the Trusted Computing Base (TCB) may be installed.
After base installation is complete one may use the Configuration Assistant (once it appears) as suggested (for root password, time adjustment etc.). If convenient, one may skip TCP/IP configuration and paging space adjustment until later.
Note: For AIX >= 5.3 the assistant offers the modification of security levels. Be careful, even the lowest level above the default may change "well known" behaviour (e.g. umask=77 rather than umask=22).
Note: Some versions offer Trusted AIX installation. Sounds good, but don't do it, unless you feel having a lack of problems.
Note: On Blade Servers (JS2x, PS70x, etc.) it is advisable to allow Serial over LAN (SOL) connections, use either smitty or 
chcons /dev/vty0
to redirect the console appropriately as soon as the first installation step is completed.

Additional Software

By default only a very minimal AIX system is installed.
You use the smitty tool to select installation media and additional SW to be installed: 
  1. Software Installation and Maintenance - Install and Update Software - Install Software 

INPUT device / directory for software              [/dev/cd0]
    assuming the standard CD/DVD device.
  2. Fill the menu: 
    * INPUT device / directory for software               /dev/cd0
* SOFTWARE to install                                [_all_latest]           +
  PREVIEW only? (install operation will NOT occur)    yes                    +
  ACCEPT new license agreements?                      yes                    +
    and use F4 (or Esc-4) to get a list of software to install. Select, start preview and check space requirements and prerequisites.
  3. Switch to 
      PREVIEW only? (install operation will NOT occur)    no                     +
    and install for real.

Some basic customizations

Before connecting to a network one should:
  1. In /etc/inetd.conf disable all unnecessary services. If the machine should offer boot services, bootps and tftp must be enabled. Activate changes by 
    refresh -s inetd

  2. chmod o-x /usr/bin/ypcat
  3. In /etc/rc.tcpip
    outcomment the start of snmpd and dpid2.
  4. In /etc/inittab
    disable several unused services by placing a colon (':') at the beginning of the line: 
    :writesrv 
:imnss 
:imqss 
:l2
... 
:l9
    httpdlite is needed for documentation display, otherwise it should be disabled too.
    The l2 entry might be needed for services such as sshd.
    The console should be activated before NIS services: 
    rctcpip:2:wait:/etc/rc.tcpip > /dev/console 2>&1 # Start TCP/IP daemons
cons:0123456789:respawn:/usr/sbin/getty /dev/console
rcnfs:2:wait:/etc/rc.nfs > /dev/console 2>&1 # Start NFS Daemons
    otherwise the machine won't boot if NIS can't be activated.
  5. Check network interface settings for 100Mbps ethernet cards.
  6. Configure the network
  7. /etc/environment
    should contain 
    YPBIND_MAXWAIT=5
    causing NIS clients to wait no longer than 5 seconds for their server, e.g. to avoid "hangs" in case of network unavailability.

Additional local software

A bunch of additional software packages I would recommend to be installed locally (i.e. on the rootvg), in order to allow minimum functionality of a standalone system. They are indicated (L) in the software catalogue. Such software may stem from various sources, e.g. AIX Bonus and other extra CDs, local software archives, mounted installp depots or even remotely mounted CDs:

Patches

After installation use 
oslevel -r
to determine the actual patch level.

Compilers

(and their patches), if available:

What's next ?

The installation as described takes about 2.2GB for AIX 5.1, about 2.7GB for AIX 5.2, about 3.5GB for AIX 5.3, and about 2.9GB (w/o compilers) for AIX 6.1, respectively (rootvg, excluding paging space).
For machines with two system disks the rootvg should be mirrored, either now or later.
After installation you will need to customize your system.
Last update: 26-Dec-2011, M.Kraemer