Raid Levels; Disk Group - NEC Express5800/R140a-4 User Manual

RAID Levels

The record mode enabling the RAID feature includes several levels. Among the levels, the on-board
RAID (MegaRAID ROMB) supports the following levels; RAID 0, RAID 1, RAID 5, RAID 6,
RAID10, and RAID 50. 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
RAID 6
RAID 10
RAID 50
NOTE:
later in this chapter.

Disk Group

A disk group is configured with more than one HDDs.
The allowable number of disk groups is equal to the number of HDDs.
The figure below shows a sample configuration. The three HDDs are connected to the Onboard
RAID Controller (MegaRAID ROMB), creating one disk group (DG).
HDD 1
(36 GB)
Number of required HDDs
Min.
1
2
3
3
4
6
For details of the RAID levels, see "RAID Levels" described
RAID Controller
HDD 2
(36 GB)
Configuring Your Server 4-37
Max.
8
2
8
8
8
8
Disk Group 0: 108 GB
HDD 3
(36 GB)