Administrator Guide

Make a Temporary Volume Available on the Secondary Group
You can make a temporary copy of a volume available on the secondary group, while providing continuous access to the original
volume on the primary group. Using a temporary copy is helpful when you want to perform an operation (such as a backup) on the
copy with no disruption to users. When the operation is completed, you can resume replicating the volume.
NOTE: This procedure assumes that the volume does not change while available on the secondary group, or — if the
volume changes — those changes are not replicated to the primary group. If you want to replicate changes, perform a
volume failover and failback procedure.
To make a temporary copy of a volume available on the secondary group and then resume replicating the volume:
1. Promote the replica set to a recovery volume. Make sure that you select the option that enables you to demote the recovery
volume.
2. Perform the desired operation on the recovery volume. (Be aware of recovery-volume restrictions when promoting an inbound
replica set to a recovery volume.)
3. Demote the recovery volume to an inbound replica set as follows:
a. Click Volumes.
b. Expand Volumes and then select the recovery volume.
c. Click Demote to replica set.
At this point, replication can continue as usual.
Replicate a Recovery Volume to the Primary Group
If the original volume on the primary group becomes available, you can replicate the recovery volume to the primary group. This
action synchronizes the data across both groups and protects the recovery volume. During the replication, initiators can continue to
access the recovery volume.
The time required to replicate the recovery volume depends on the presence of the failback snapshot on the primary group. The
failback snapshot establishes the failback baseline, which is the point in time at which the volume on the primary group and the most
recent complete replica on the secondary group have the same data. If the failback snapshot exists, only the changes made to the
recovery volume are replicated. If the failback snapshot does not exist, the rst replication is a complete copy of the recovery volume
data.
The following restrictions and considerations apply:
• You cannot replicate a recovery template volume.
• Dell recommends that you replicate the recovery volume to the primary group immediately before failing back to the primary
group, because the volume is oine during the nal replication that is part of failing back to the primary group.
• During the procedure, you can choose to perform a required replication by using manual transfer replication.
If you choose to use manual transfer replication, the status of the Create Replica task is in-progress until you complete the
manual transfer replication. When the manual transfer replication is complete, the Replicate to Partner operation continues
automatically.
• The Replicate to Partner operation is available only if the primary group and the secondary group are running PS Series rmware
version 5.0 or greater. If you do not meet this requirement, you must manually perform the Replicate to Partner procedure.
• You must stop all replications of the recovery volume to the primary group before permanently promoting a replica set.
To replicate a recovery volume to the primary group:
1. Obtain the name and password for a group administrator account on the primary group.
2. Click Volumes.
3. Expand Volumes and then select the recovery volume.
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