Disk Array Terms - Western Digital WD Serial ATA RAID Controller User Manual

Disk Array Terms

Disk Array Description
A disk array is formed from a group of two or more hard drives that appear to the system as a
single drive. The advantage of an array is to provide better throughput performance and/or
data fault tolerance.
Better performance is accomplished by sharing the workload among multiple physical drives.
Fault tolerance is achieved through data redundancy operation where if one (or more) drive
fails or has a sector failure, a mirrored copy of the data can be found on another drive(s).
For optimal results, select identical SATA drives to install in disk arrays. The drives' matched
performance allows the array to function better as a single drive.
Disk Array Member
The individual hard drives in an array are called members. Each member of a specific disk
array has coded in its reserved sector configuration information that identifies the drive as a
member. All disk members in a formed disk array are recognized as a single physical drive to
the system.
Disk Array Types
For most installations, the EasyBuild setup Auto Setup (1) option will configure your system.
There are two disk array types (RAID 0 and 1) in two categories that can be installed on the
WD SATA RAID Controller. Striping is in the Performance category while Mirroring is in
the Fault Tolerance category.
Disk arrays within the Performance and Fault Tolerance categories conform to the
Redundant Array of Independent Disks technology, or RAID. The RAID levels supported are
0 and 1.
RAID Level Performance
RAID 0 (Striping)
RAID 1 (Mirroring)
Fault Tolerance
Highest No
Normal Yes
WD SERIAL ATA RAID CONTROLLER
Capacity No. of Drives
No. Drives x
Smallest Size
Smallest Size Drive
DISK ARRAY CONCEPTS - 6
USER MANUAL
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