Chapter 3 Setup
3.3 Optimizing Volume Configurations
ETERNUS DX60 S2 Disk storage system User’s Guide -Operation-
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Copyright 2012 FUJITSU LIMITED P3AM-5512-03ENZ0
3.3.1 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 cus-
tomer needs. The redistribution of volumes and reconfiguration of RAID groups (e.g. changing
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 for simultaneous RAID Migration operations is 32.
•A total volume capacity of up to 8TB can be used for simultaneous RAID Migration
operations.
•The volume type that can be migrated is "Open". RAID groups can be selected as the RAID
Migration destination.
•RAID Migration cannot be performed when the source volume type is "SDV" or "SDPV".
•Select RAID groups with an unused area that is more than the capacity of the RAID Migration
source volume.
•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 server, pre-migration, migrating and post-migration volumes are accessed
indistinguishably.
•During RAID Migration, the access performance for the RAID groups that are specified as the
RAID Migration source and RAID Migration destination may be reduced.
•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.
•When RAID Migration is used to increase the volume (LUN) capacities, note that the
increased size of the expanded volumes may not always be dynamically re-recognized by the
server, depending on the server-side OS (type and version) being used. Refer to the
applicable OS and file system documentation before dynamically expanding the volume
capacity.
This is not necessary when building a new system after the volume capacity has been
expanded.
3.3.2 Logical Device Expansion (LDE)
Logical Device Expansion (LDE) allows the capacity of an existing RAID group to be dynamically
expanded by the addition of extra disks. By expanding the capacity of existing RAID group, a
new volume can be added without having to add new RAID groups.
This section describes the restrictions and notes on using LDE.
For details on the LDE procedure, refer to "ETERNUS Web GUI User's Guide" or "ETERNUS
CLI User's Guide".
•A RAID group can be specified as a target for LDE.
•Multiple LDEs cannot be performed simultaneously.