I have been receiving errors when backing up 2 databases on our SQL server. See example below. The workaround I have been using is to take the database offline, bring it back online, run backup again and it runs fine. Seems to happen every couple of days or so. The database log file definately exists.
SQL Server: Windows 2003 x64 R2 Service Pack 2, SQL Server 2008 Service pack 1
Backup software: Commvault 9, Service Pack 5a
Description: Error encountered during backup. Error: [The log for database 'example' is not available. Check the event log for related error messages. Resolve any errors and restart the database. A nonrecoverable I/O error occurred on file "09f8be50-067a-408c-a656-4f358805e9b3:" 995(failed to retrieve text for this error. Reason: 1815). BACKUP DATABASE is terminating abnormally. An exception occurred while executing a Transact-SQL statement or batch.]
Appreciate any suggestions.