Optimization Of Volume Configurations; Table 38 Optimization Of Volume Configurations - Fujitsu ETERNUS DX S5 Series Design Manual

2. Basic Functions

Optimization of Volume Configurations

Optimization of Volume Configurations
The ETERNUS DX allows for the expansion of volumes and RAID group capacities, migration among RAID groups,
and changing of RAID levels according to changes in the operation load and performance requirements while
the system is running. There are several expansion functions.
Table 38 Optimization of Volume Configurations
Function/usage
RAID Migration
Logical Device
Expansion
LUN Concatenation
Wide Striping
¡: Possible, ´: Not possible
*1: For TPVs or FTVs, the capacity cannot be expanded during a migration.
●
Expansion of Volume Capacity
RAID Migration (with increased migration destination capacity)
•
When volume capacity is insufficient, a volume can be moved to a RAID group that has enough free space.
This function is recommended for use when the desired free space is available in the destination.
LUN Concatenation
•
Adds areas of free space to an existing volume to expand its capacity. This uses free space from a RAID
group to efficiently expand the volume.
●
Expansion of RAID Group Capacity
• Logical Device Expansion
Adds new drives to an existing RAID group to expand the RAID group capacity. This is used to expand the
existing RAID group capacity instead of adding a new RAID group to add the volumes.
●
Migration among RAID Groups
• RAID Migration
The performance of the current RAID groups may not be satisfactory due to conflicting volumes after
performance requirements have been changed. Use RAID Migration to improve the performance by
redistributing the volumes amongst multiple RAID groups.
●
Changing the RAID Level
• RAID Migration (to a RAID group with a different RAID level)
Migrating to a RAID group with a different RAID level changes the RAID level of volumes. This is used to
convert a given volume to a different RAID level.
• Logical Device Expansion (and changing RAID levels when adding the new drives)
The RAID level for RAID groups can be changed. Adding drives while changing is also available. This is
used to convert the RAID level of all the volumes belonging to a given RAID group.
RAID group
Volume expansion
expansion
´
¡ (Adding capacity
during migration)
(*1)
´
¡
´
¡ (Concatenating
free spaces)
´ ´
Migration among Changing the RAID
RAID groups level
¡ ¡
´
¡ (Adding drives to
existing RAID
groups)
´ ´
´ ´
74
Striping for RAID
groups
´
´
´
¡
Design Guide