Refreshing a snapshot

Periodically refresh or update your snapshot or set of snapshots so they contain a current copy of the original volumes. Refreshing a snapshot is a two-step process. During the first step, the Snap Back operation reattaches a snapshot volume to its original volume and uses Fast Resync to automatically update the snapshot mirror and synchronize it with the original volume, applying only the changes tracked in the Disk Change Object (DCO) volume. This process takes less time than the traditional method of copying the entire original volume to the returning mirror. In the second step, the Snap Shot operation is performed to detach the snapshot mirrors again, creating a new point-in-time copy of the database. If you are creating multiple snapshots, the SFW GUI Snap Shot command or the vxsnap CLI command must be used to snapshot all the database and log volumes simultaneously. This step is done without taking the database offline.

The Snap Back and vxsnap commands can be called from either the bpend_notify.bat file in NetBackup or from a batch file in a pre/post command to run at the completion of a Backup Exec for Windows Servers backup job. Additionally, a script could be written and used with the Windows Task Scheduler to automatically update the snapshot or set of snapshots on a regular basis.