SQL database snapshots enable you to quickly revert a database back to the state it was in when the database snapshot was created. When you use a database snapshot, a full restore of the host database is not required to revert the database. However, that changes made to the host between the time a database snapshot is created and the point at which it is reverted, are lost.
The Backup Exec SQL Agent works with the SQL database to create database snapshots, which are read-only, point-in-time copies of an existing host database. When Backup Exec runs a SQL backup job using the Database Snapshot (SQL 2005 or later) backup method, a request is sent to the host database instructing it to create a database snapshot.
Database snapshots cannot be backed up to storage media. Rather, they are written to a SQL snapshot file on disk. After running the database snapshot job, Backup Exec creates history and job log information to indicate the job’s status.
Because database snapshots cannot be backed up, all database snapshots will be lost if the disk where the host database is installed fails. Therefore database snapshots should not be used as your sole database protection strategy. They should be used in conjunction with an overall Backup Exec database protection strategy that includes full, differential, and transaction log backups of the SQL database.