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
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.
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.