Dell POWERVAULT MD3620I - Manual (Page 175)

Configuration: Premium Feature—Snapshot Virtual Disks 175
• Rolling back a base virtual disk to a snapshot virtual disk does not affect
the contents of the snapshot virtual disks.
• Only one snapshot rollback operation can be performed at a time.
• While a base virtual disk that is undergoing a rollback, you cannot create a
new snapshot virtual disks from that base virtual disk.
• A snapshot rollback cannot be started while any of these operations are
underway:
–
Virtual Disk Capacity Expansion
– Virtual Disk Expansion (VDE)
– RAID Level Migration
– Segment Size Migration
– Virtual Disk Copy
– Role Reversal (in remote replication)
• If the base virtual disk is a secondary virtual disk in a remote replication,
you cannot perform a snapshot rollback.
• If any capacity used in the associated snapshot repository virtual disk
contains unreadable sectors, the snapshot rollback fails.
If an error occurs during the rollback, the operation is paused and the base
virtual disk and snapshot virtual disk displays Needs Attention icons. The
RAID controller module also logs the event to the Major Event Log (MEL).
Follow the Recovery Guru procedure to correct the error and repeat the
rollback operation.
WARNING: Risk of data loss: If you cancel a snapshot rollback in progress, the
base virtual disk may remain in an unusable state and the snapshot virtual disk
displays as failed in the MD storage management software. Therefore, do not
cancel a snapshot rollback unless reliable recovery options exist for restoring the
content of the base virtual disk.
Command Line Options
Optionally, you also can use the command line interface (CLI) to start,
cancel, resume or modify priority of a snapshot rollback. For more
information, see the CLI Guide.
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