Fujitsu Eternus web GUI - Page 118

Chapter 6 RAID Group Management
6.2 Functions in the Action Area for RAID Group
ETERNUS Web GUI User’s Guide
118
Copyright 2011 FUJITSU LIMITED P2X0-1090-02ENZ0
The maximum number of RAID groups for each model
The maximum number of RAID groups varies depending on each model. The following table
shows the maximum number of RAID groups for each model.
Drive combinations that can configure a RAID group
The following table shows the drive combinations that can configure a RAID group.
There are two methods to create a volume: automatic drive selection and manual drive selection.
Model The maximum number of RAID
groups
ETERNUS DX80 S2 60
ETERNUS DX90 S2 120
ETERNUS DX410 S2 240
ETERNUS DX440 S2 480
Online Nearline SSD
Online OK OK NG
Nearline OK OK NG
SSD NG NG OK
• RAID groups can be created when the drives satisfy all of the following
conditions:
- The drives are not registered in any RAID group, TPP, or REC Disk
Buffer
- The drives are not registered as hot spares
- The "Status" is "Present"
• All drives that are selected for creating a RAID group must have the
same capacity and the same speed. If drives of different capacities exist
in a RAID group, the smallest capacity becomes the standard, and all
other drives are regarded as having the same capacity as the smallest
drive. In this case, the remaining drive space is not used. In addition, if
drives of different speeds exist in a RAID group, the access perfor-
mance of the RAID group is reduced by the slower drives.
• Some combinations of drive types cannot configure a RAID group.
Refer to "Drive combinations that can configure a RAID group" (page
118) for details.
• If both Online disks and Nearline disks are used for a RAID group, the
drives in the RAID group will have different speeds and capacity. In this
case, some space cannot be used and the performance is reduced.
• RAID0 has no data redundancy. The use of RAID1+0, RAID5, RAID6,
RAID5+0, or RAID1 is recommended.