Raid Migration - Fujitsu Eternus DX80 S2 User Manual

Chapter 3 Setup
3.4 Data Management
• Logical Device Expansion (and changing RAID levels when adding the new drives)
The RAID level may also be changed when adding new drives to a RAID group. This is used
to convert the RAID level of all the volumes belonging to a given RAID group.
3.4.1

RAID Migration

RAID Migration is a function that transfers a volume to a different RAID group while guaranteeing
the integrity of the data. By using RAID Migration, RAID groups and volumes can be hot
switched. This allows easy redistribution of volumes among RAID groups in response to
customer needs. The redistribution of volumes and reconfiguration of RAID groups (e.g. chang-
ing the RAID level from RAID5 to RAID1+0) can be performed while the system is running.
This section describes the restrictions and notes on using RAID Migration.
For details on the RAID Migration procedure, refer to "ETERNUS Web GUI User's Guide" or
"ETERNUS CLI User's Guide".
• Volumes can be specified as a target for RAID Migration.
• The maximum number of volumes in simultaneous RAID Migration operations is 32 volumes.
• The total capacity of volumes in simultaneous RAID Migration operations is up to 128TB.
• The volume types that can be migrated are "Standard/Open" and "TPV" (Thin Provisioning
Volume). RAID groups and Thin Provisioning Pools (TPPs) can be selected as the RAID
Migration destination.
The following four combinations of volume types (migration source volume → migration
•
destination volume) are supported:
-
-
-
-
• RAID Migration cannot be performed when the source volume type is "SDV" or "SDPV".
• Select RAID groups under any of the following conditions for the RAID Migration destination:
-
-
• TPPs under any of the following conditions cannot be selected as the RAID Migration
destination.
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-
*1:
• RAID levels that are supported by the ETERNUS DX Disk storage system can be set for the
source and destination RAID groups.
• The final volume number (LUN) will be the same as the initial volume number, and from the
point of view of the host, pre-migration, migrating and post-migration volumes are accessed
indistinguishably.
• If the power is turned off or an electrical power outage occurs during RAID Migration, the
process will simply continue when the power is restored.
ETERNUS DX80 S2/DX90 S2 Disk storage system User's Guide -Operation-
Standard/Open volume → Standard/Open volume
Standard/Open volume → TPV
TPV → Standard/Open volume
TPV → TPV
The RAID group is not registered as the REC Disk Buffer.
The RAID group has an unused area that is more than the capacity of the migration source
volume.
When the TPP capacity is less than the capacity of the migration source volume (*1)
When the capacity of the migration source volume is equal to or larger than the maximum
TPP capacity for each model
When the migration source is a TPV, the migration source volume capacity indicates the used
capacity (physical capacity allocated from TPP).
Copyright 2011 FUJITSU LIMITED
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