Hi all,
I have this weird notion that upgrading the TL does not cause the machine to wipe, but upgrading a major version (from aix 6 to 7) means it's actually a fresh install and will wipe the date and i have to install the software again (TSM server, for instance). Trying to google it, i came across references to migration vs upgrade, and hoped maybe i can upgrade my server to aix 7 while keeping all installed software, but dind't find any further explanation.
Well I did an upgrade from 6.1 to 7.1 and dont remember having changes anything TSM but then it was not TSM server... but the SAS software seemed to work though I upgraded the software shortly after (the reason I gave to pass from 6.1 to 7.1 ...) the issues I had was I suppose because I was not the primary installer of the server and when it was given to me in 6.1, I found out it was upgraded from 5.3.. because I did suffer a little... I had trouble with cups also, so to play safe I do hope you have rootvg in mirror, split the mirror and keep the alternate in order to mount it and compare the executable and paths if some issues arise... about CUPS I just copied the executables where the previous admin replaced the original command by them, I did this time document the thing, renamin the new originals as .aix_ori, the CUPS by .cups and linked to classical cammnad name e.g. lp
But this was 2 years ago... I may have forgotten...
This is definitely not the case. A TL update and a version update differ only in scope (of the replaced OS software), but not in principle.
Having said this, a fresh install when updating to a new version might be a good idea, because you have the opportunity to "clean up" the system. But it is not mandatory at all.
A "migration" (or "alternate disk migration") works like this (principle only): You have a system with 2 (mirrored) rootvg disks. You break the mirror so that you have two independent copies of your rootvg. One of these is used to do the update (or fresh install). Then you have the opportunity to test everything. Once you are finished testing you remirror again, either booting from the old disk (this would wipe out your update and reinstate what you had) or booting from the updated disk (this way destroying the old version).
The gain is: at every time you have a working copy of a known-to-work configuration and you can step back and start over at any time should anything not work as expected. Google for "alternate disk install" or "alternate disk migration". Related searches would be "multibos": basically several versions/configurations residing side by side, similar to a multiboot PC.
