Figure 3 Raid1+0 Concept; Figure 4 Raid5 Concept - Fujitsu ETERNUS AF250 Design Manual

1. Function
RAID Functions
●
RAID1+0 (Striping of Pairs of Drives for Mirroring)
RAID1+0 combines the high I/O performance of RAID0 (striping) with the reliability of RAID1 (mirroring).

Figure 3 RAID1+0 Concept

A
Mirroring
Drive#0
●
RAID5 (Striping with Distributed Parity)
Data is divided into blocks and allocated across multiple drives together with parity information created from
the data in order to ensure the redundancy of the data.

Figure 4 RAID5 Concept

A
A
E
I
M P
Drive#0
Data writing request
A
B
Mirroring
Drive#1
A'
Drive#4
Data writing request
A B C D
B C
B C
F G P
P
I, J, K, L
J
N
M, N, O, P
Drive#1 Drive#2
Parity for data A to D: P A, B, C, D
Parity for data E to H: P E, F, G, H
Parity for data I to L: P I, J, K, L
Parity for data M to P: P M, N, O, P
FUJITSU Storage ETERNUS AF250 S2, ETERNUS AF250 All-Flash Arrays Design Guide (Basic)
Copyright 2019 FUJITSU LIMITED
B C D
C
Mirroring
Drive#2
B'
Drive#5
D
Create parity data
P
D A, B, C, D
H
E, F, G, H
K L
O P
Drive#3 Drive#4
18
D
Mirroring
Drive#3
C'
Drive#7
Drive#6
Striping (RAID0)
Mirroring (RAID1)
P3AG-1822-09ENZ0
D'