Verify that you have good colds before you go through.
Almost every change or upgrade plan I have starts off with:
- Day after colds: Verify backups for hosts {a,b,c,d,e,f,g,h}
- Day of implementation: Verify backups for hosts {a,b,c,d,e,f,g,h}
If that backup isn't good, either take a good backup immediately before preceding or reschedule your implementation for a window after the next full backup.
I've had this save me a time or two. A previously bulletproof backup decided to cook off the week of one of my upgrades.
