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SnapProtect Snapshot Operations

Snapshots of the data created by the SnapProtect backup are available for various operations like list, mount, unmount, delete, or revert.

Mount and Unmount Snapshots

The mount operation is used to present the hardware snapshot from a storage array to the host computer and to make the snapshot accessible on a mount point. Mount operations can be part of snap restore job, user-initiated GUI mount, Live Browse mounts for deferred catalog agents (like VMware), or part of snap backup copy job.

Conversely, the unmount operation is used to remove the mount point on the host computer where the snapshot is mounted and to remove the mapped hardware snapshot from the host computer. Unmount operations are needed once the job is done with the mounted snapshot.

Mount and Unmount operations are applicable to all agents.

For Oracle, Oracle RAC, SAP Oracle, and Sybase, you have the option to mount snapshots on a MediaAgent computer.

It is recommended that you select the option to protect a snapshot before it is mounted, as this ensures the changes made to the snapshot when it is mounted are not retained when you unmount the snapshot and the snapshot is usable for data protection operations.

When mounting multiple snapshots, note the following:

  • You can mount snapshots from different jobs.
  • The snapshots that you select for mounting should belong to the same agent, such as Windows File System, UNIX File System, Oracle, Microsoft SQL, VMware, etc.
  • The snapshots must be mounted on a MediaAgent that has the same OS. For example, Linux volumes should be mounted on Linux MediaAgent.
  • There are no limits on the number of snapshots to be mounted. However, the greater the number of selected snapshots , the greater the time for mounting thesnapshots.
  • When mounting Oracle ASM snapshots, the destination client must have a +ASM instance configured in addition to having the Oracle iDataAgent and MediaAgent installed.
  • For Virtual Server Agent (VSA), mount snapshots from the backup set or subclient level. Mounting snapshots from the storage policy is not supported.
  • For VMware, mounting multiple snapshots of the same volume at the same time is not supported.

To mount or unmount snapshots, refer to Mounting and Unmounting Snapshots.

Delete Snapshots

Applicable to all agents.

To delete a snapshot, refer to Deleting Snapshots.

Revert a Snapshot

The revert operation overwrites any modification to the data since the time when the snapshot was created. This operation is available if the storage array that you are using supports revert.

Use the revert operation to bring the data back to the point-in-time when the snapshot was taken. You can either perform an application aware revert or a hardware specific revert.

Warnings:

  • It is recommended to verify the contents of the backup and ensure that you want to perform a revert operation as it is an irreversible operation.
  • If you plan to perform a revert operation, you will not be able to use the associated storage policy for further auxiliary copy operations.

Application Aware Revert

To revert a snapshot with application aware revert, refer to Reverting Snapshots with Application Aware Revert.

Hardware Specific Revert

To revert a snapshot with hardware specific revert, refer to Reverting Snapshots with Hardware Specific Revert.

Revert a Virtual Machine from a Snapshot

You can revert a virtual machine from a snapshot. The revert operation is faster than the regular restore operation because files are directly copied from the snapshot to their original volumes. It is useful when you want to bring the data back to the point-in-time when the snapshot was taken.

To revert a virtual Machine form a snapshot, refer to Reverting a Virtual Machine from a Snapshot.

View Snapshot Details

The List Snaps operation enlists snapshots created for an agent, job, or a snapshot copy. The list of the snapshots corresponds to the entity selected, for example, listing snapshots for an agent displays all the snapshots created for the selected agent.

List Snaps and use the Snaps created during SnapProtect operation dialog box displays a list of all subclient snapshots that includes information about each snapshot, including the source mount path, snap mount path, the storage array, the source client, and volume or disk related information for the snapshots. Refer to Viewing Snapshots Details.

Applicable to all agents.

Snap Pruning

If a SnapProtect backup job fails in backup phase, a prune request is sent immediately and deletes the snaps that belong to the SnapProtect operation on the storage array. For example, if a SnapProtect operation is in pending state after taking snaps for a data volume, then it deletes the snap for that data volume. Once the job resumes, it takes a snap again from data phase. As deletion is performed immediately, you do not need to wait for the data aging job to delete unuseful snaps.

Snap Reconciliation

Snapshots may be deleted from the array due to factors like low disk space on the array, number of snapshots exceeds the threshold, etc. Jobs corresponding to deleted snapshots can no longer be used for any data recovery or backup copy operations. You can use the nRunSnapRecon additional setting to start snap reconciliation to check for missing snapshots once in every 24 hours and marks jobs corresponding to the missing snapshots as invalid or you can use on-demand Reconciliation in the Array Management GUI.

To add or edit an additional setting, follow the steps in Add or Modify an Additional Setting.

For more information about on-demand Reconciliation, refer to the Array Management GUI Operations.

SCSI Reservation

When you need to enable SCSI reservation for SnapProtect backup, use the  nSCSIReserveForSnap additional setting. Enabling SCSI reservation prevents other applications (SCSI3 compliant) from using the reserved SCSI Device (for example, the mounted snapshot).

Applicable to all agents.

If this option is enabled and the hardware does not support this type of operation, subsequent backup jobs may fail.

To add or edit an additional setting, follow the steps in Add or Modify an Additional Setting.