Migrating or moving a volume, Changing the data protection level – HP LeftHand P4000 SAN Solutions User Manual
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3.
In the Size field, change the number and change the units if necessary.
4.
Click OK when you are finished.
CAUTION:
Decreasing the volume size is not recommended. If you shrink the volume in the CMC
before shrinking it from the server file system, your data will be corrupted or lost.
Changing the data protection level
1.
In the Data Protection Level list, select the level of Network RAID you want.
Network RAID-10 is recommended for all production volumes.
IMPORTANT:
If you change a volume to Network RAID-5 or Network RAID-6, you should
also change the provisioning type to thin.
2.
Click OK when you are finished.
Migrating or moving a volume
Editing the volume to change the cluster causes the volume to migrate to the target cluster. The
LeftHand OS software allows the online migration of volumes between storage clusters in the same
management group. This migration can be used to manage both storage capacity and performance
between clusters. For example, you might move a large volume from Cluster A to Cluster B to free
up space in Cluster A, or improve the performance of a volume by moving it from a cluster of
MDL-SAS drives in a storage system to a cluster of 15K SAS drives in a storage system.
See
for the requirements for migrating a volume.
iSCSI sessions and volume migration
iSCSI sessions are rebalanced during volume migration. While data is being migrated the volume
is still accessible and fully functional. The rebalancing affects systems using the DSM for MPIO
differently than systems that are not using the DSM for MPIO.
•
Using DSM for MPIO—Administrative sessions are rebalanced to the new cluster immediately
upon volume migration. DSM sessions go into an unknown/failed state and are then
re-established on the second cluster within a short period of time.
•
No DSM for MPIO—iSCSI session is rebalanced to the new cluster immediately on volume
migration.
Before, or as soon as possible after beginning the migration, the iSCSI initiators configured to
access this volume must be re-configured to connect to the VIP of the new cluster. Some initiators
require you to disconnect the volume, re-configure the initiator to use the new cluster VIP as a target
address, and then connect to the volume again. Since this volume is disconnected, administrators
should schedule a maintenance window for the re-configuration of the initiator.
NOTE:
Moving the volume to a different cluster requires restriping the data in both clusters.
Depending on volume sizes and workload on the cluster, restriping can take hours, or even days.
To migrate the volume:
1.
In the navigation window, select the volume you want to edit.
2.
Click Volume Tasks and select Edit Volume.
3.
On the Edit Volume window, click the Advanced tab.
4.
In the Cluster list, select a different cluster.
5.
Click OK.
160 Using volumes