What is your biggest screwup in your IT career? I'd like to hear about accidentally typing "rm -r *" as root and later realizing you were in / instead of the right directory. host A held the primary copy of a 4Tb database for host B (which normally ran in parallel and would have mirrors synced periodically) and host C which was for backups. database on host A was screwed and image on backup was worthless. i accidentally synced some of A's disks over B and some of B's disks over A, thus making all data on both servers worthless. had to restore from tape to C, sync back C over A and then sync back A over B for full copies across the board. we had about a 16 hour outage while we made all kinds of changes to our production SAN on the fly.