ETERNUS DX60/DX80/DX90 Disk storage system User Guide - Fujitsu

Chapter 1 Overview
1.3 Functions
1.3.5 Logical Device Expansion
Logical Device Expansion (RAID Group Expansion) allows the capacity of an existing RAID
group to be dynamically extended by the addition of extra disks. By using Logical Device
Expansion to extend the capacity of existing RAID group in this way, new volume can be added
without having to add new RAID groups, as used to be the case.
The following shows the example when RAID5(3+1) 300GB configuration converted to a
RAID5(4+1) configuration by the addition of an extra disk.
RAID5(3+1)
300GB 300GB 300GB 300GB
LUN0 600GB
LUN1 300GB
RAID5(4+1)
300GB 300GB 300GB 300GB 300GB
LUN0 600GB
LUN1 300GB
LUN2 300GB
300GB
Figure 1.15 Example for use Logical Device Expansion
Unused
44
ETERNUS DX60/DX80/DX90 Disk storage system User Guide
Copyright 2011 FUJITSU LIMITED P3AM-3042-08ENZ0