HP-UX 11i Version 2 Installation and Update Guide, May 2005

Choosing an Installation Method
Supported Update Paths to HP-UX 11i v2
Chapter 346
NOTE Updating from a release of HP-UX to another release of HP-UX that was
released earlier in time is not supported. For example, trying to update
from HP-UX 11i v1 December 2004 release to the HP-UX 11i v2
September 2004 release is not supported. This could cause system
incompatibilities and unpredictable results. If you attempt to update to
an earlier version of HP-UX, the update process will stop without
making any changes to your system and you will get the following error
message:
ERROR: You are attempting to update from your release
of HP-UX to a version of HP-UX that was released earlier in
time. This is not supported. The update process has stopped
without making any changes to your system. Please see the
'Supported Update Paths' section of the HP-UX 11i v2
Installation and Update Guide for more
information.