Solaris

What is the easiest or preferred way to roll back the solaris cluster patches?

My guess is to do a flash archive pre-patch and then install off of that if it doesn't work.

Any other ideas?

remove a whole patchcluster is a bad thing to do... but it "should" work. never done something like this so it's up to you to try it .
boot in single user mode and use the "patch_order" (from the patchcluster) file in reverse for the "patchrm" command.

the better way is a mirrored rootdisk which is splitted before patching and if problems occure, just boot from the second disk and you are back to the old system. this can be done (and is good practice) via "live upgrade". also the flasharchive is a good option to rollback to the old system...

Any clue how to set up mirroring on V440? I'm having troubles finding an installation guide.

it's the same on all systems with two disks. and it depends on the os an the os version. so, on the v440 you can use hardware-mirror (which you have to setup BEFORE os installation; using "raidctl") or software-mirror with sds or with zfs if you are on solaris 10 (best on latest version which is update 8).

By the way, if you use ZFS, you can clone your ZFS root and patch it without any mirroring in place, just like OpenSolaris does with snap upgrade.
This is unsupported but anyway here is an example:
Patching a Live Solaris 10 System Without Live Upgrade