2-2
Chapter 2: RAID configuration
2.1
Setting up RAID
The RAID card supports RAID 0, RAID 1, RAID 1E, and RAID 10.
2.1.1
RAID definitions
RAID 0
(Data striping) optimizes two identical hard disk drives to read and write data in
parallel, interleaved stacks. Two hard disks perform the same work as a single drive but at a
sustained data transfer rate, double that of a single disk alone, thus improving data access
and storage. Use of at least two new identical hard disk drives is required for this setup.
RAID 1
(Data mirroring) copies and maintains an identical image of data from one drive to a
second drive. If one drive fails, the disk array management software directs all applications
to the surviving drive as it contains a complete copy of the data in the other drive. This RAID
configuration provides data protection and increases fault tolerance to the entire system. Use
two new drives or use an existing drive and a new drive for this setup. The new drive must be
of the same size or larger than the existing drive.
RAID 1E
(Enhanced RAID 1) has a striped layout with each stripe unit having a secondary (or
alternate) copy stored on a different disk. You can use three or more hard disk drives for this
configuration.
RAID 10
is a striped configuration with RAID 1 segments whose segments are RAID 1 arrays.
This configuration has the same fault tolerance as RAID 1, and has the same overhead for
fault-tolerance as mirroring alone. RAID 10 achieves high input/output rates by striping RAID
1 segments. In some instances, a RAID 10 configuration can sustain multiple simultaneous
drive failure. A minimum of four hard disk drives is required for this setup.
If you want to boot the system from a hard disk drive included in a created RAID set, copy
first the RAID driver from the support CD to a floppy disk before you install an operating
system to the selected hard disk drive.
2.1.2
Installing hard disk drives
The RAID card supports SAS for RAID set configuration. For optimal performance, install
identical drives of the same model and capacity when creating a disk array.
To install the SAS hard disks for RAID configuration:
1.
Install the SAS hard disks into the drive bays following the instructions in the system
user guide.
2.
Connect a mini-SAS HD cable to the connector on the back plane and to the mini-SAS
HD connector on the card.
3.
Connect a power cable to the power connector on each drive or on the back plane.
