Dell PowerFlex 4.5.x Administration Guide

Migrate a snapshot vTree

You can migrate a volume tree (vTree) for a snapshot to a different storage pool. Volumes undergoing migration remain available for I/O.

NOTE:vTree migration is a long process and can take days or weeks, depending on the size of the vTree.

The following limitations apply:

Migration between storage pools with different data layouts is only allowed if there is a single volume in the vTree.
vTrees containing a manually created snapshot cannot be migrated.
You cannot migrate a volume that is a source volume of a snapshot policy between storage pools with different data layouts.
Volumes involved in replication cannot be migrated.

On the menu bar, click Protection > Snapshots.
In the list of snapshots, select the desired snapshot.
In the right pane, click View Details.
In the left pane, click the VTree tab.
In the left pane, from the VTree menu on the right, select Migrate vTree.
In the Migrate vTree dialog box, in the TARGET area, select the destination storage pool.
The storage pool's free capacity is displayed. Ensure that you select a storage pool with enough capacity for the vTree size.

Optionally, select one or more of the following advanced options:

Option	Description
Add migration to the head of the migration queue	Give this vTree migration the highest priority in the migration priority queue.
Ignore destination capacity	Allow the migration to start regardless of whether there is enough capacity at the destination.
Enable compression	A compression algorithm is applied to the data.
Convert vTree from...	Convert a thin-provisioned vTree to thick-provisioned, or a thick-provisioned vTree to thin-provisioned at the destination, depending on the provisioning of the source volume. NOTE:SDCs with a version earlier than v3.0 do not fully support converting a thick-provisioned vTree to a thin-provisioned vTree during migration; after migration, the vTree will be thin-provisioned, but the SDC will not be able to trim it. These volumes can be trimmed by unmapping and then remapping them, or by restarting the SDC. The SDC version will not affect capacity allocation and a vTree converted from thick to thin provisioning will be reduced in size accordingly in the system.
Save current vTree provisioning state during migration	The provisioning state is returned to its original state before the migration took place.

Click Migrate vTree.

The vTree migration is initiated. The vTree appears in both the source and the destination storage pools.
At the top right of the page, click the Running Storage Jobs icon, and check the progress of the migration.
Verify that the operation has finished and was successful, and click Dismiss.