Bull NovaScale R460 E2, User Manual, Page: 106 / 490

4-22 Configuring Your Server
RAID CONFIGURATION
This section describes how to use the internal hard disk drives as RAID System by Internal RAID Controller.
About the optional RAID Controller, refer to the documents provided with optional RAID Controller.
RAID
Overview of RAID System
What is RAID (Redundant Array of Inexpensive Disks)?
RAID is an abbreviation for "Redundant Array of Inexpensive Disks". The RAID technology allows more than one hard disk
drive (HDD) to be handled collectively.
In actual, RAID can configure more than one HDDs as a single array (disk group) to operate the HDDs effectively. This can
bring higher performance than a single HDD of a large capacity.
The Internal RAID Controller has a feature to divide a single disk group into several logical drives. Operating system
recognizes these virtual disks as if it were a single HDD. Operating system accesses to more than one HDD configuring a disk
group in parallel.
Some RAID levels can recover data from remaining data and parity by using rebuild feature if an error occurs in a single HDD.
This can provide high reliability for the system.
RAID Levels
The record mode enabling the RAID feature includes several levels. Among the levels, the Internal RAID Controller supports
the following levels; RAID 0, RAID 1, RAID 5, and RAID 6. The number of HDDs required to create a disk group varies
depending on the RAID level as shown in the table below.
Number of required HDDs
RAID level
Min. Max.
RAID 0 1 8
RAID 1 2 2
RAID 5 3 8
RAID 6 3 8
IMPORTANT: To use RAID 5 or RAID 6, you need to additionally install the optional RAID
Upgrade Kit.
NOTE:
For details of the RAID levels, see "RAID Levels" described 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 Internal RAID Controller , creating one
disk group (DG).