Is there a way to determine, when an account attempts to open a DB and fails, which DB it was trying to open?
Possibly via a server-side trace?
For example, this morning I had an account attempt to open a DB and fail with the "Failed to open the explicitly specified database" error. There's no indication in the SQL logs of a DB going into recovery, the server did not reboot, and there were no backup / maintenance jobs running at the time this happened that might have caused a problem.
Every time this happens (not that frequently, but enough,) our security software catches the "Login failed for user..." bit, and I get someone over asking what might have happened.