SQLVDI error - attempt to release mutex not owned by caller
- by Chris W
I've started getting some errors in the App event log of one of our database servers (Windows 2003 & SQL Server 2005).  The nightly full database backups are completing successfully however immediately after the job success is written to the event log there is a run of entries that say:
  SQLVDI: Loc=CVDS.
  Desc=Release(ClientAliveMutex).
  ErrorCode=(288)Attempt to release
  mutex not owned by caller.
There's five of these logged - the server itself has more than 20 databases on it which are all backed up successfully.
The server is backed up by Bacula using a VSS backup.
Has anyone got any ideas what would be causing the errors?  They seem to have started after a re-boot on Friday to install some patches which included KB960089.
Edit:
After getting the errors for a few days they've now stopped without any action on my part other than letting the backups continue as they were.  It may be a coincidence but they stopped after Bacula completed its weekly full rather than the daily incremental backup.