Migrating AIX 5.1 => 5.2

IMPORTANT!
Found that the prngd subsystem on AIX 5.1 is incompatible with the AIX 5.2 upgrade. BEFORE migration this subsystem should be disabled either in /etc/rc.local or erased completely: 
rmssys -s prngd
It has to be remade after migration (see customization).
If prngd is not disabled, the final boot after 5.2 installation coredumps with 0C9 and the machine never recovers.
In this case:
  1. Boot into maintenance mode (needs first 5.2 CD and SMS console)
  2. Limited function shell (or getrootfs)
  3. vi /etc/rc.local to disable prngd

Firmware/Microcode upgrade

It is wise to update the firmware/microcode of your system before upgrading the system. Checkout the IBM support site Directly via ftp site.

Base system

Straightforward like installing from scratch. When asked, select "Migration" instead of "Overwrite" installation.
Last update: 26-Jul-2006, M.Kraemer