HP StorageWorks SAN Virtualization Services Platform Manager User Guide (5697-0454, May 2010)

6. Select the Hierarchy tab. The Hierarchy tab displays the original source virtual disk or VDG and
the entire snapshot hierarchy dependent on that source element, including the PiT you started
with, which you can identify by name in the hierarchy.
Rolling back virtual disks and VDGs
Rollback is a recovery operation that removes all data modifications that were made to a virtual disk,
VDG, or VDG snapshot since the creation of a specified PiT. The snapshot structure preceding the
creation of the selected PiT is maintained. Rollback is enabled only when the virtual disk, VDG, or
VDG snapshot has a snapshot structure that includes only PiTs and no snapshots. Rollback can be
activated using any PiT from a virtual disk, VDG, or VDG snapshot. All data and PiTs with timestamps
later than the specified PiT are destroyed.
To roll back a virtual disk, VDG, or VDG snapshot:
1. Remove all snapshots from all PiTs on the virtual disk, VDG, or VDG snapshot.
2. Unmount the virtual disk, VDG, or VDG snapshot on all hosts that are using it. Perform any other
steps for rollback described in the user manual for using the specific operating system with VSM.
CAUTION:
Do not perform a rollback while the application using the virtual disk or VDG is online,
because data integrity will not be maintained, since rollback makes the server cache obsolete
because the content of the device is changing. Just before the rollback, the application is
presented with the current data. Immediately after the rollback, the application is presented
with the data of a PiT that may be a day or two old. Therefore, unmount the virtual disk or
VDG on all hosts that use it prior to performing rollback.
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