Fujitsu ETERNUS DX100 S4 Design Manual page 56

2. Basic Functions
Optimization of Volume Configurations
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 vol-
umes.
●
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 per-
formance 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.
●
Striping for Multiple RAID Groups
• Wide Striping
Distributing a single volume to multiple RAID groups makes I/O access from the server more effi-
cient and improves the performance.
Fujitsu Storage ETERNUS DX100 S4/DX200 S4, ETERNUS DX100 S3/DX200 S3 Hybrid Storage Systems Design Guide (Basic)
56
Copyright 2023 Fujitsu Limited
P3AM-7642-32ENZ0