NEC BladeServer Express5800 Series User Manual page 86

RAID Levels
The record mode enabling the RAID feature includes several levels. Among the levels, the on-board
RAID (LSI Logic MegaRAID SAS PCI EXPRESS ROMB) supports the following levels;
RAID 0, RAID 1, and RAID 5. The number of HDDs required to create a disk group varies
depending on the RAID level as shown in the table below.
RAID level
RAID 0
RAID 1
RAID 5
Striping of RAID 1
Striping of RAID 5
NOTE:
later in this chapter.
Disk Group
A disk group is configured with more than one HDDs.
Up to five disk groups are permitted by the on-board RAID (LSI Logic MegaRAID SAS PCI
EXPRESS ROMB) when five HDDs are installed in the server.
The figure below shows a sample configuration. The three HDDs are connected to the on-board
RAID (LSI Logic MegaRAID SAS PCI EXPRESS ROMB), creating one disk group (DG).
HDD 1
(36 GB)
Number of required HDDs
Min.
1
2
3
4
6
For details of the RAID levels, see "RAID Levels" described
Disk array controller
HDD 2
(36 GB)
Configuring Your Server 4-29
Max.
6
2
6
4
6
Disk Group 0: 108 GB
HDD 3
(36 GB)