NEC Storage Manager - Page 309

Appendix C RAID
19
(6) RAID50
Stripe 6
Stripe 3
Stripe N
Parity (N, N+1)
Parity (7, 8)
Parity (3, 4)
Stripe 8
Stripe 1
Stripe 2
Stripe 3
Stripe 4
Stripe 5
Stripe 6
Stripe 7
...
Parity Generation
Data Sent from Host
4 5 6
Stripe N+1 Striping Size
Stripe 1
Stripe 5
Parity (9, 10)
Stripe 2
Physical Disk 1 2
Parity Generation
Stripe 8
Stripe 9 Stripe 10 Stripe N
Parity (1, 2)
Stripe 4
Parity (5, 6)
Stripe 7
Stripe 9 Stripe 10
3
This method, based on RAID0, slices data sent from the host and distributes the slices into
multiple sets of RAID5 physical disks.
Since RAID50 distributes data to multiple sets of RAID5 disks, it enables further concurrent
processing and provides quicker access.
<Advantage>
y Concurrent processing for multiple R/W commands
y Quick access
<Disadvantage>
y If one of the physical disks constituting logical disks fails, performance in read operation
lowers.