Color Of Code

Font Size

SCREEN

Profile

Layout

Menu Style

Cpanel

System

Main source: http://en.wikipedia.org/wiki/RAID

RAID = Redundant Array of Inexpensive Disks (old), Redundant Array of Independent Disks (new)

Goals: Improve data reliability / I/O throughput

Key concepts:

Mirroring: copying data other disks

Striping: distributing data among disks

Parity: Redundant information for reliability and error correction

RAID 0 (at least 2 drives)

Striping: content is dispatched through the discs. No redundancy, highest I/O. Usage for scratch workspace which needs high speed and no reliability. One disk failure leads to unrecoverable data loss.

RAID 1 (at least 2 drives)

Mirroring: content is copied to all disks. There is only small or no I/O speed benefit, but a data redundancy and safety.

RAID 5 (at least 3 drives)

Parity information is distributed on the drives. If only one drive fails, the data is still safe. This RAID level also gives a higher performance and is one of the most used modes.