About data migration, Notes on migrating data, 75 notes on migrating data – HP XP P9000 Command View Advanced Edition Software User Manual
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About data migration
Data migration involves moving data from one set of volumes to another set of volumes or THP/Smart
pools, including those in externally-connected storage systems. For example, you can migrate data
when your volume performance decreases or your environment changes. When relocating data based
on the results of performance monitoring for volumes being used by servers and applications, or when
migrating data from an old storage system to a newly set-up storage system, the data in multiple
volumes can be migrated to other volumes or THP/Smart pools.
The source volume can be selected by host or by logical group. The source volume also can be selected
from some of the volumes allocated to a host some of the volumes in a logical group, some of the
volumes in a tier. Migration source volumes can also be selected from volume search results. If a
volume that cannot be migrated is included in the selected volumes, that volume is excluded from
migration and only volumes that can be migrated, will be migrated.
Migration targets are selected from tiers, THP/Smart pools, or resource search results. If THP/Smart
pools are selected, THP/Smart volumes with the same capacity as the migration-source volumes are
automatically created. The existing THP/Smart volumes also can be specified as migration targets.
Note the following:
•
When the migration source and the migration target are selected, individual pairs of migration
source volumes and migration target volumes (or THP/Smart pools) are automatically created.
Although, you can change these pairs, pairs of volumes that cannot be migrated will not be created.
•
During migration, data can still be accessed.
•
When data migration is completed normally, the LDEV ID and host I/O of the migration source
volumes are changed to those of the migration target volumes. The procedure for accessing migrated
data is not changed before or after migration.
•
If linked with HP StorageWorks P9000 Performance Advisor software, parity group busy rate for
the migration source volume and migration target volume can be checked.
•
After migrating, you can delete the data of the source volumes.
•
After volumes are migrated to a THP/Smart volumes, unused capacity in the target volumes is re-
turned to the pool (zero page reclaim) if the zero page reclaim option is on.
•
You cannot work with volumes (such as copy pair or volume allocation) until the migration tasks
are completed.
You must have a Tiered Storage Manager license registered to perform Data Migration.
For details about data migration in Legacy mode, using migration groups earlier than v7.1.1, see
“
Notes on migrating data
•
The number of volumes that are candidates for migration target volumes are narrowed down and
displayed when selecting a migration target volume. If you want to display all the volumes, set a
value for the
migration.plan.candidateVolumeCountLimit
property in the
migra-
tion.properties
file. For details on the properties file, refer to the HP P9000 Command View
Advanced Edition Suite Software Administrator Guide. To avoid insufficient memory, we recommend
that you use the default.
•
Data migration tasks take a long time from start of execution to completion. This might affect the
performance of access from hosts to target volumes. To avoid executing such tasks while the access
frequency is high, check the time required to complete the tasks and set a task execution schedule
before registering the tasks. Actual required time might differ considerably in cases such as per-
forming migration for the first time, migrating a volume smaller than 170 GB, or migrating many
volumes at the same time.
User Guide
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