Rolling back a Solaris boot environment

Boot environments have been with us since Solaris 10. In my experience it started out pretty buggy but in the last year or so its been stable. It really has revolutionized patching for me in terms of cutting down risk,time and effort.

In Solaris 11, boot environments are pretty much built into how you do patching. ("Patching" is a bit of a misnomer in Solaris 11 - "updating/upgrading" are more appropriate terms.)

Recently I had to roll back to a previous boot environment two weeks after the implementation. Rolling back is pretty easy (activating the previous boot environment and rebooting), however, you do lose changes you've made to the OS in the meantime. You can mitigate this risk by mounting the other boot environment and comparing files between the two.

Areas you should check are:

1. /etc/system and any other config files in /etc
2. Crons
3. Zone configurations
4. Files in root's home directory and other home directories.

These are just the basics, hopefully if you've made any major changes since then, you've documented it well enough to figure out how to re-implement then if needed.