User`s manual

The Introduction of RAID A-5
User’s Manual
Disk 0 Disk1 Disk 2 Disk3
3 Parit
y
A 2
A 1
A 0
B 3
2 Parit
y
B 1
B 0
C 3
C 2
1 Parit
y
C 0
D 3
D 2
D 1
0 Parit
y
ABCD
DATA
D BlockC BlockB BlockA Block
RAID Level 5
Independent Data disks with
distributed parity blocks
RAID 5 also stripes data at a block level
across several drives. But it distributes
parity among the drives, which avoids the
write bottleneck caused by the single
dedicated parity drive. Each drive takes
turns storing parity information for a
different series of stripes. RAID 5 can
execute read/write to disk drives either in
parallel or independently.