The issue was with SQL backups failing in SQL 2008 server due to the SQL Server VSS writer as posted by the user in the forum.


When backup is occurring through SQL VDI Backups
, it requires 3 threads to perform the backups for a single database. The link below clearly tells how the SQL VDI Backups work.

So when the database Auto Close Property is set to true and when a thread from the SQL VDI Backup tries to freeze the IO on the database to take the backup it might fail with this error:

Event 9001

The log for database '' is not available. Check the event log for related error messages. Resolve any errors and restart the database.

It might also be followed by some other errors which are mentioned in the forum's thread.

If the database is configured for Auto Close Property set to true then, when there is no user activity on the database, the database will automatically close. As a best practice the Auto Close Property should be set to false.

and also

SQL Server and Auto Close Setting


The errors might occur due to SQL Server not able to open the database quickly enough for the backup to complete or the database was in the middle of shutting down due to previous user activity on the database. So setting the Auto Close property of the database to false will have the SQL VDI Backups to complete successfully.

See Also

Backup error and solutions

This entry participated in the Technology Guru TechNet WiKi for July 2013 contest and Won the bronze award.