Accusys ExaRAID GUI - Manual (Page 265)

Appendix
A-9
A.8 RAID 30
RAID 30 arrays are formed by striping data across RAID 3 sub-arrays. This
offers better performance than RAID 3 alone but does not have the
speed of a pure RAID 0 array. Storage efficiency and fault tolerance vary
depending on the number and size of sub-arrays compared to the array
as a whole. RAID 30 resembles RAID 50 in terms of characteristics but is
more suitable for handling large files.
RAID 30: Byte striping with parity combined with block striping
Characteristics
• Storage capacity = [(number of disks in each subarray) -1] x (number of
subarrays) x (capacity of the smallest disk)
• A minimum of six disks are required.
• Good fault tolerance, in general
• Increased capacity and performance compared to RAID 3
Recommended use
• Multimedia
• File servers
• Large databases
Striping
A
E
I
M
C
G
K
O
P
AC
P
EG
P
IK
P
MO
B
F
J
N
D
H
L
Q
P
BD
P
FH
P
JL
P
NQ
RAID 3 RAID 3
AC
EG
IK
MO
BD
FH
JL
NQ
E
F
Logical Volume
A . . . Q
Figure A-7 RAID 30 disk array