I'm always asking questions on here, so I thought today I'd give back and tell you a tale of what happened in my production environment recently.
So we had a power loss at our main office on a Friday arvo last week, not unusual for our area, not a problem as we have a backup generator that kicks in automatically within 10 seconds to take over the load.
Unfortunately, it appears that some muppet had earlier, hit the emergency stop button on the generator which knocked it out of automatic mode, so when the power went out, the UPS's lasted 20 minutes then everything went dark.
My whole production environment got shutdown dirty. Ew.
So I raced into my office when I saw the UPS notifications, fixed the generator and got everything powered back up.
I then spent the next 45 minutes slowly bringing all my servers online and praying that nothing had corrupted.
Luckily, everything appeared to have surprised the dirty shutdown!
That night though when I ran my Veeam backups, I got warnings about the CBT (Changed block tracking) in the form of "Cannot use CBT: Soap fault. Error caused by file "
The backups still completed, but it was pretty damn slow.
So I did some digging and it appears that the CBT somehow got corrupted from the dirty shutdown

Luckily I was able to find this KB article (http://www.veeam.com/KB1113) which outlines how to reset CBT.
Which basically involves shutting down each vm (oh yay) disabling CBT on the VM, removing the old CBT files from the vmfs then rebooting the VM a couple of times.
Yay fixed


Morale of the story, never underestimate the power of human stupidity.