Figure 6 Raid6 Concept - Fujitsu ETERNUS DX500 S4/DX600 S4 Design Manual

2. Basic Functions
RAID Functions
●
RAID6 (Striping with Double Distributed Parity)
Allocating two different parities on different drives (double parity) makes it possible to recover from up to two
drive failures.

Figure 6 RAID6 Concept

A
A
E
I
M P1
Drive#0
FUJITSU Storage ETERNUS DX500 S4/DX600 S4, ETERNUS DX500 S3/DX600 S3 Hybrid Storage Systems Design Guide (Basic)
Data writing request
A B C D
B C
B C
F G P1
P2
J P1
I, J, K, L
P2
M, N, O, P M, N, O, P
Drive#1 Drive#2
Parity for data A to D: P1
Parity for data E to H: P1
Parity for data I to L: P1
Parity for data M to P: P1
Copyright 2019 FUJITSU LIMITED
D
Create parity data
P1 P2
A, B, C, D
D
P2
E, F, G, H E, F, G, H
I, J, K, L K
N O
Drive#3 Drive#4
and P2
A, B, C, D
and P2
E, F, G, H
and P2
I, J, K, L I, J, K, L
and P2
M, N, O, P
20
A, B, C, D
H
L
P
Drive#5
A, B, C, D
E, F, G, H
M, N, O, P
P3AM-7722-25ENZ0