Starting Rolling Back a Snapshot Group

Prerequisites

• For all snapshots in the snapshot group, their Running Status is Activated and Health Status is Normal.
• To ensure data consistency, the source LUN group is unmapped before the snapshot rollback.

Precautions

• You can roll back only one snapshot of a source LUN at a time.
• If the source LUN of a snapshot is also the local or remote LUN of a HyperMetro pair, the snapshot can be rolled back only after the HyperMetro pair is paused.

  If the source LUN of a snapshot is also the remote LUN of a HyperMetro pair and is a thin LUN, you are advised to roll back the snapshot only after the initial synchronization of the HyperMetro pair is complete. Otherwise, data inconsistency may occur.

• If the source LUN of a snapshot is also the primary LUN of a remote replication pair, the snapshot can be rolled back only after the pair's status becomes Split.

  You cannot roll back a snapshot if its source LUN is the secondary LUN of a remote replication pair.

• You cannot roll back a snapshot if its source LUN is the primary LUN of a clone pair.

  You can roll back a snapshot if its source LUN is used as the secondary LUN of a clone pair, the pair's Pair Running Status is Split, and the pair's Data Status is Consistent or Reverse inconsistent.

• Rollback cannot be performed when the source LUN or snapshot is being expanded.

• If a snapshot and its source LUN have different capacities, you can roll back the snapshot after their capacities are the same.

Procedure

1. Log in to DeviceManager.
2. Choose Data Protection > Snapshot > LUN Group/Application.
3. Click LUN group.

   For OceanStor 18000 V5, 18000F V5, 18000 V5 Kunpeng, and 18000F V5 Kunpeng series, choose Data Protection > Snapshot > LUN Group.

4. In the upper function pane, select a snapshot group and choose More > Start Rollback.

   The Start Rolling Back Snapshot dialog box is displayed.

5. Set the snapshot rollback speed.
   1. From the Rollback Speed drop-down list, select a rollback speed. Available speeds are Low, Medium, High, and Highest.
      • When the service load on the storage system is heavy, set the rollback speed to Low or Medium.
      • When the service load on the storage system is light, set the rollback speed to High or Highest.
      • Low: When the speed is set to low, the rollback will take a long time. This value is applicable when the service load is heavy. Without considering other operations' impacts on the storage system, the speed is normally from 0 to 5 MB/s.
      • Medium: When the speed is set to medium, the rollback will take a relatively short period. This value is applicable when the service load is relatively heavy. Without considering other operations' impacts on the storage system, the speed is normally from 10 to 20 MB/s.
      • High: When the speed is set to high, the rollback will take a short period. This value is applicable when the service load is relatively light. Without considering other operations' impacts on the storage system, the speed is normally from 50 to 70 MB/s.
      • Highest: When the speed is set to highest, the rollback will take the shortest period. This value is applicable when the service load is light. Without considering other operations' impacts on the storage system, the speed is normally above 100 MB/s.
   2. Click OK.

      The security alert dialog box is displayed.

6. Start rolling back the snapshot.
   1. Confirm the information in the dialog box, select I have read and understand the consequences associated with performing this operation, and click OK.

      The Execution Result dialog box is displayed, indicating that the operation succeeded.

   2. Click Close.