Jonathan Kehayias (via Paul Randal) advises caution:
Recently I received an email with a very vague description of a problem that went something along the lines of:
“After some issues with Windows patching and rolling back from snapshots, our cluster resources won’t come online. In the process of troubleshooting the issue and validating the fix, we rolled back a few times. We can’t find any details about the issue in the cluster logs, Windows event logs, or SQL Server error log to investigate further.”
Read on for more information about the immediate problem, the root cause, and the actual issue the customer ran into before compounding the problem.