Figure 3 Raid1+0 Concept; Figure 4 Raid5 Concept - Fujitsu ETERNUS DX100 S4 Design Manual

2. Basic Functions
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 (mir-
roring).

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 Drive#1
Fujitsu Storage ETERNUS DX100 S4/DX200 S4, ETERNUS DX100 S3/DX200 S3 Hybrid Storage Systems Design Guide (Basic)
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#2 Drive#3
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
Copyright 2023 Fujitsu Limited
B C D
C
Mirroring
Drive#2
B'
Drive#5
Create
D
parity data
P
A, B, C, D
D
H
E, F, G, H
K L
O P
Drive#4
18
D
Mirroring
Drive#3
C'
Drive#7
Drive#6
Striping (RAID0)
Mirroring (RAID1)
P3AM-7642-32ENZ0
D'