Administrator Guide

○ Changing the segment size of a virtual disk.
• You cannot start a rollback operation if the base virtual disk is participating in a virtual disk copy.
• You cannot start a rollback operation if the base virtual disk is a secondary virtual disk in a remote replication. However, if the base
virtual disk is the primary virtual disk in a remote replication, you can start a rollback operation. Additionally, you cannot perform a role
reversal in a remote replication if the primary virtual disk is participating in a rollback operation.
• A rollback operation fails if any of the used capacity in the associated snapshot repository virtual disk has unreadable sectors.
NOTE: You also can use the command line interface (CLI) to start a rollback operation from multiple snapshot images
concurrently, cancel a rollback operation, resume a rollback operation, modify the priority of a rollback operation, and
view the progress of a rollback operation.
Starting snapshot rollback
1. From the AMW, select the Storage & Copy Services tab.
2. Do one of the following:
• Select a snapshot image of a base virtual disk and then select Copy Services > Snapshot Image > Rollback > Start.
• Select a consistency group snapshot image, and then select Copy Services > Consistency Group Snapshot Image > Rollback
> Start.
Depending on your selection, either the Confirm Rollback Snapshot Image or the Confirm Rollback Snapshot Image window is
displayed.
3. If you are starting the rollback operation from a consistency group snapshot image, select the member virtual disks from the member
virtual disks table that you want to rollback; otherwise skip to step 4.
4. In the Rollback priority area, use the slider bar to set a priority for the rollback operation.
• There are five priority rates available: lowest, low, medium, high, and highest.
• If the priority is set at the lowest rate, I/O activity is prioritized and the rollback operation takes longer time to complete.
• If the priority is set at the highest priority rate, the rollback operation is prioritized, but I/O activity for the storage array may be
affected.
5. To confirm and start the rollback operation, type yes in the text box, and click Rollback.
You can view the progress of the rollback operation in the Properties pane when you select the base virtual disk or the consistency
group member virtual disk in the Logical pane.
Resuming a snapshot image rollback
Use the Resume Rollback option to resume a rollback operation that is in a Paused state. The rollback operation is paused if an error
occurs during the rollback operation.
1. From the AMW, select the Storage & Copy Services tab.
2. Select a snapshot image of either a base virtual disk or of a consistency group’s member virtual disk and then select Copy Services >
Snapshot Image > Rollback > Resume.
The Confirm Resume Rollback window is displayed.
3. Click Resume.
The following may occur depending on the error condition:
• If the resume rollback operation is successful — You can view the progress of the rollback operation in the Properties pane when
you select the base virtual disk or the consistency group member virtual disk in the Logical pane.
• If the resume rollback operation is not successful — The rollback operation is paused again. The base virtual disk or member virtual
disk displays Needs Attention icons, and the controller logs the event to the Major Event Log (MEL). You can follow the Recovery
Guru procedure to correct the problem or contact your Technical Support representative.
Canceling snapshot image rollback
Use the Cancel Rollback option to cancel a rollback operation after it has been started. You can cancel an active rollback that is in
progress (actively copying data), a pending rollback (in a pending queue awaiting resources to start), or a rollback that has been paused
due to an error. When you cancel a rollback operation as it is in progress, the base virtual disk reverts to an unusable state and appears as
failed in the MD Storage Manager. Therefore, consider canceling a rollback operation only when recovery options exist for restoring the
content of the base virtual disk.
After you cancel a rollback operation, you must take one of the following actions:
Premium feature—Snapshot Virtual Disk
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