Dell PowerVault MD3200i - Manual (Page 151)

Configuration: Premium Feature—Snapshot Virtual Disks 151
To implement this backup, select the first virtual disk and create a backup
schedule that runs once a day, Monday through Friday, at a time between the
end of the work day and 11PM. Do not select an end date. Apply the same
schedule to the second virtual disk, then map the two snapshot virtual disks
to your backup host server and perform your regular backup procedures.
Remember to unmap the two resulting snapshot virtual disks before the next
scheduled snapshot begins. If the snapshot virtual disks are not unmapped,
the storage array does not perform the next scheduled snapshot operation in
order to avoid data corruption.
Scheduled snapshots are also valuable in the event of a data loss. For example,
if you back up your data at the end of every work day and keep hourly
snapshots from 8AM to 5PM, data can be recovered from the snapshots in
windows smaller than one hour. To accomplish this type of rapid recovery,
create a schedule that contains a start time of 8AM and an end time of 5PM,
then select 10 snapshots per day on Monday through Friday with no end date.
For more information on creating snapshot virtual disk schedules, see the
following sections on creating snapshots.
Guidelines for Creating Snapshot Schedules
Certain guidelines apply when creating snapshot virtual disk schedules:
• Scheduled virtual disk snapshot operations do not occur if:
– The snapshot virtual disk is mapped
– The storage array is offline or powered off
– The snapshot virtual disk is in use as a source virtual disk during a
Virtual Disk Copy operation
– A copy operation is Pending or In progress
• Deleting a snapshot virtual disk that contains a schedule also deletes the
schedule
• Snapshot schedules are stored in the configuration database on the storage
array. The Management Station does not need to be running for scheduled
snapshot operations to occur.
• Snapshot schedules can be created when the snapshot virtual disk is
initially created or can be added to existing snapshot virtual disks.
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