I have a UPS installed, but the power failures are extended (couple of hours) and UPS eventually runs out
This happened about 5 or 6 nights in a row
There was other orruption as well, but fsck seem to sorted it
The big problem was mail not starting up due to the corrupted perl modules.
But all is fine now, and the guys are shutting down the server in the evenings if they cannot start the generator during power failures.