Asus PIKE 1078 - Manual (Page 16)

2-2 Chapter 2: RAID configuration
2.1 Setting up RAID
The RAID card supports RAID 0, RAID 1, RAID 10, RAID 5, RAID 50, RAID 6, and
RAID 60 set(s).
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 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.
RAID 5
stripes both data and parity information across three or more hard
disk drives. Among the advantages of RAID 5 configuration include better
HDD performance, fault tolerance, and higher storage capacity. The RAID
5 configuration is best suited for transaction processing, relational database
applications, enterprise resource planning, and other business systems. Use a
minimum of three identical hard disk drives for this setup.
RAID 50 is a combination of RAID 0 and RAID 5. It uses distributed parity and disk
striping and works best with data that requires high reliability, high request rates,
high data transfers, and medium-to-large capacity.
Having RAID 0 and RAID 5 virtual disks in the same physical array is not
recommended. If a drive in the physical array has to be rebuilt, the RAID 0
virtual disk will cause a failure during the rebuild.
RAID 6 stripes dual parity to provide fault tolerance from two drive failures; array
continues to operate with up to two failed drives. This makes larger RAID groups
more practical, especially for high availability systems. With dual parity, RAID 6
gives time to rebuild the array without the data being volatile while the failed drive
is being recovered.