Using snapshot technology with the SQL Agent

Last published : Apr 02, 2026
Backup Exec uses snapshot technology by default for SQL Server backups. The SQL Agent supports full snapshot backups using Microsoft's Volume Shadow Copy Service (VSS), a snapshot provider service only available on Windows 2008 or later. The use of snapshot technology can reduce both restore time and backup performance on the server.
When you submit a backup job that uses snapshot technology, a snapshot of each volume is created, providing a point-in-time record of the data. Backup Exec uses snapshot technology to momentarily suspend write activity to a volume so that a snapshot of the volume can be created. The data is then backed up from the snapshots, and then the snapshots are deleted.
Note: Use snapshot technology with jobs that use deduplication devices.
Before you use snapshot technology with the SQL Agent, review the following information:
  • With snapshot technology, a point-in-time view of the SQL database is "snapped" and then backed up, leaving the actual SQL database open and available for users.
  • SQL backups that use snapshot technology are considerably larger than regular SQL backups (also known as streaming backups).
  • Performing consistency checks before backup is strongly recommended.
  • The SQL Agent supports only full snapshot backups; transaction log snapshots and differential snapshots are not supported.
  • With the SQL Agent, snapshot and streaming backups are interoperable when you restore SQL data.
  • Performing database consistency checks both before and after backups affects the time required for the backup jobs.
The following SQL backup options are not supported with snapshot backups:
  • Use checksums on backup (SQL 2005 or later)
This option is used as a redundancy check, and works with the Run verify only and do not restore data restore option.
  • SQL Server 2008 Enterprise Edition software compression
  • Create on-disk copies of SQL backups to be placed on the SQL Server where the database is located
    Note: Microsoft Virtual Shadow Copy Service (VSS) snapshots are not the same as SQL database snapshots. VSS snapshots enable you to create point-in-time snapshots of disk volumes and shares; database snapshots enable you to create point-in-time copies of SQL databases.
See Using database snapshots for SQL Server.
More Information
Configuring Backup Exec to run a consistency check before every SQL backup