8 data migration, Migration overview, Migrating data – HP XP Racks User Manual
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8 Data migration
This chapter discusses using Continuous Access Synchronous to migrate data from one storage
system to another.
Migration overview
Continuous Access Synchronous can be used to move data from one system to another. Data is
typically migrated for the following reasons:
•
To copy data to a new volume
•
To temporarily move data from an LU to accommodate other activities (for example, to make
repairs)
•
To relocate LUs in order to balance workloads and distribute I/O activity evenly within or
across storage systems
You do not need to use host migration software is unnecessary for data migration when using
Continuous Access Synchronous. Also, Continuous Access Synchronous data migration does not
affect the host.
In a data migration, the entire contents of a volume are copied to the secondary volume (P-VOL to
S-VOL). The volumes are identical when the copy operation completes. The volumes are then usually
released from the Continuous Access Synchronous pair.
If you need to migrate data from other vendors' storage systems to a XP7 system, contact your HP
account team.
Migrating data
1.
Make sure that the data path is installed, and Continuous Access Synchronous configuration
procedures are completed. See
“Cnt Ac-S configuration” (page 45)
for details.
2.
Vary the target volume (S-VOL) offline from all attached hosts. The source volume (P-VOL) can
remain online.
3.
In Remote Web Console, connect to the storage system where the volume to be migrated is
located. Create the Continuous Access Synchronous pair or pairs. See
as needed.
When pair status changes to PAIR, the operation is completed. You can monitor the progress
of the operation from the Remote Replication window.
4.
If you are not using RAID Manager commands and host software to complete the migration,
continue the following procedure to stop using the P-VOLs and switch to the S-VOLs:
1.
Stop all host updates to the P-VOLs.
2.
When all update activity to the P-VOLs has stopped, connect to the MCU, select the correct
CU, and release the Continuous Access Synchronous pairs.
3.
If the P-VOL and S-VOL are attached to the same host, vary the P-VOL offline, then vary
the S-VOL online. Use this order because the P-VOL and S-VOL have the same volume
labels and cannot be online to the same host at the same time.
4.
If you want to keep the volumes synchronized, establish the same Continuous Access
Synchronous pairs in the reverse direction using the None initial copy option. If the original
P-VOLs will be temporarily unavailable for update copy operations, you can split the new
pairs (pairsplit-r) so that the new MCU keeps track of changes.
5.
Start the applications with the S-VOLs. When the original P-VOLs become available, you
can resynchronize the pairs.
If the original P-VOL is temporarily unavailable for update copy operations, split the new pair so
that the new primary system keeps track of changes.
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Data migration