You do not need to create a back up immediately after a cold
install.
The Ignite-UX product is not available for making a system
recovery backup at the time of the initial release of HP-UX 11i Version 1.5.
When it is released, it will be available for download from HP's
Software Depot:
Before Ignite-UX is available, once you have begun putting
additional files on your system we recommend using the fbackup command to create a backup archive and frecover to restore the system if necessary. By backing up your
system, you will have a reliable system image to return to if subsequent
system changes or failures corrupt your system.