Precautions when making backups of SQL databases
Precaution: In some cases VSS can trigger SQL Server 2005 to perform full backups automatically. This can lead to useless differential backups of databases.
Upon restoring your database, this can result in an unexpected failure.
The SQL Server 2005 Sp2 installation will activate SQL Writer Service. This service will automatically write a full backup to the Shadow Volume if VSS is activated and open files are written to the Shadow Volume. This can happen upon any event in which OnlineBackupClient encounters a locked file and addresses the VSS interface to get a shadow copy of this file.
Configure OnlineBackupClient correctly by either switching off the SQL Writer Service in case you wish to make a backup of SQL databases using OnlineBackupClient or switch off VSS in OnlineBackupClient options.