File System Snapshot


File System Snapshot, a built-in feature of the UNIX operating system, is supported by the ContinuousDataReplicator on UNIX, and is used to create point-in-time snapshots of volumes. These snapshots do not involve bitmaps, so only full volume copies are possible; you cannot create incremental snapshots.

For CDR on UNIX, File System Snapshots are employed in the SmartSync Scan phase, and can also be used when creating Recovery Point on a destination computer. For more information about about the SmartSync Scan phase see Job Phases; for more information about Recovery Points, see Recovery Points.


In Linux, File System Snapshots are managed by Logical Volume Manager (LVM); therefore, they will only work with a mounted logical volume and not with a cxbf device.


To configure File System Snapshots for CDR on UNIX:

  1. Install ContinuousDataReplicator on a supported platform.

  2. Specify a Snap Engine on both the source and destination, as needed.

Specify a Snap Engine

Before You Begin

  • In the source computer:

    • For Windows 2003 or higher, VSS is used as the default snap engine.
  • This procedure only applies to the destination computer.

  • In the CommCell Browser, right-click the Replication Set on the source computer and select Properties.

  • In the Replication Options tab, select one of the choices in the Select Snap Engine Type for Recovery Point Creation section.

    For Windows, VSS is the default selection; ONTAP can be used if available on the destination computer where the Recovery Point will be created.

    For UNIX, Snap Engine Type is automatically detected by the File System configured on the destination computer.

  • Click OK to save your changes.

    On UNIX, CDR software automatically recognizes the File Systems configured on the destination computer and detects the appropriate snap engine.


A product license for the ContinuousDataReplicator is required on the source and destination computers; no extra license is required for the File System Snapshot feature.

For general information about licensing, see the Commvault Licensing Program Guide.