RAID

November 25, 2018
computer storage

Redundant array of independent disks.

With the exception of RAID 1 providing merely speed advantages, RAID systems fall into one of the two categories:

Provides

Configurations

Common:

Others:

remark: For the below representations, assume each disk is of 1TB capacity.

RAID 0

Disk 0 Disk 1
A1 A2
A3 A4
A5 A6
A7 A8

RAID 1

Disk 0 Disk 1
A1 A1
A2 A2
A3 A3
A4 A4

RAID 2

Disk 0 Disk 1 Disk 2 Disk 3 Disk 4 Disk 5 Disk 6
A1 A2 A3 A4 Ap1 Ap2 Ap3
B1 B2 B3 B4 Bp1 Bp2 Bp3
C1 C2 C3 C4 Cp1 Cp2 Cp3
D1 D2 D3 D4 Dp1 Dp2 Dp3

RAID 3

Disk 0 Disk 1 Disk 2 Disk 3
A1 A2 A3 Ap(1-3)
A4 A5 A6 Ap(4-6)
B1 B2 B3 Bp(1-3)
B4 B5 B6 Bp(4-6)

RAID 4

Disk 0 Disk 1 Disk 2 Disk 3
A1 A2 A3 Ap
B1 B2 B3 Bp
C1 C2 C3 Cp
D1 D2 D3 Dp

RAID 5

Disk 0 Disk 1 Disk 2 Disk 3
A1 A2 A3 Ap
B1 B2 Bp B3
C1 Cp C2 C3
Dp D1 D2 D3

RAID 6

Disk 0 Disk 1 Disk 2 Disk 3 Disk 4
A1 A2 A3 Ap Aq
B1 B2 Bp Bq B3
C1 Cp Cq C2 C3
Dp Dq D1 D2 D3

RAID 10(1+0)

Disadvantages of RAID:

Resources