Administrator Guide

The system performs the following:
• Creates the schedule for the snapshot group or consistency group and updates the Properties pane for the snapshot group or
consistency group.
• If you had selected Create the First Snapshot Image Now, the system takes a copy of the associated base virtual disk. Each
subsequent snapshot image capture depends on the schedule you created.
Editing a snapshot schedule
Use the Edit Snapshot Image Schedule option to modify the schedule settings defined for a snapshot group or consistency group. You
can also use the Edit Snapshot Image Schedule option to temporarily suspend scheduled snapshot image creation by disabling the
schedule. When a schedule is disabled, the scheduled snapshot image creations do not occur.
To edit a schedule:
1. From the AMW, select the Storage & Copy Services tab.
2. Select the snapshot group or consistency group for which you want to edit a schedule.
3. Do one of the following:
• Copy Services > Snapshot Group > Edit Snapshot Image Schedule.
• Copy Services > Consistency Group Snapshot Image > Create/Edit Schedule.
The Edit Snapshot Image Schedule window is displayed.
4. Do one of the following:
• If you want to disable the schedule, de-select Enable Snapshot Image Scheduling.
• If you want to use a different existing schedule, click Import settings from existing schedule. The Import Schedule Settings
dialog is displayed. Select the new schedule you want to import from the Existing schedules table and then click Import.
• If you want to edit the schedule, modify the schedule settings.
5. Click OK to apply your changes to the schedule for the snapshot group or consistency group you selected.
Performing snapshot rollbacks
You can rollback snapshot operations by either:
• Creating a snapshot virtual disk of a snapshot image, which allows you to retrieve deleted files from that snapshot virtual disk (the
base virtual disk remains undisturbed).
• Restoring a snapshot image to the base virtual disk, which allows you to roll back the base virtual disk to a previous point-in-time.
NOTE:
The host will have immediate access to the new-rolled-back base virtual disk, but the existing base virtual disk
will not allow the host read-write access after the rollback is initiated. You can create a snapshot of the base virtual disk
just before you start the rollback to save the pre-rollback base virtual disk for recovery purposes.
Snapshot images are useful any time you want to roll back to a known good data set at a specific point in time. For example, before
performing a risky operation on a virtual disk, you can create a snapshot image to enable “undo” capability for the entire virtual disk. You
can start a rollback from the following types of snapshot images:
• Snapshot image of a base virtual disk, which allows you to roll back the base virtual disk associated with a snapshot group to a
previous state.
• Consistency group snapshot image, which allows you to roll back all or select member virtual disks of the consistency group to a
previous state.
Snapshot rollback limitations
• The rollback operation does not change the content of the snapshot images that are associated with the base virtual disk.
• You cannot perform the following actions when a rollback operation is in progress:
○ Delete the snapshot image that is being used for the rollback.
○ Create a new snapshot image for a base virtual disk that is participating in a rollback operation.
○ Change the associated snapshot group’s Repository-Full Policy.
• You cannot start a rollback operation when any of these operations are in progress in the storage array:
○ Expanding the capacity of a disk group.
○ Virtual disk Expansion (VDE) to increase the capacity of a virtual disk.
○ Migrating a disk group to a different RAID level.
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Premium feature—Snapshot Virtual Disk