Raid 50 Arrays - Adaptec 4000SAS Installation And User Manual

RAID 50 Arrays

A RAID 50 array is built from six to forty-eight disk drives configured as
two or more RAID 5 arrays, and stripes stored data and parity data
across all disk drives in both RAID 5 arrays. (For more information, see
RAID 5 Arrays on page
Note: Because the Adaptec 2420SA RAID controller can't support more
than four disk drives, it can't support RAID 50 arrays.
The parity data provides data protection, and striping improves
performance. RAID 50 arrays also provide high data transfer speeds.
Drive segment size is limited to the size of the smallest disk drive in the
array. For example, three 250 GB disk drives and three 400 GB disk
drives comprise two equal-sized RAID 5 arrays with 500 GB of stored
data and 250 GB of parity data. The RAID 50 array can therefore
contain 1000 GB (2 x 500 GB) of stored data and 500 GB of parity data.
RAID 50 Logical Drive = 1000 GB plus Parity
RAID 5
A
1, 5, P 3, P, 9
Drive 1 Drive 2
250 GB 250 GB
In the example above, P represents the distributed parity data.
Appendix B: Understanding RAID
84.)
500 GB Data Storage each
250 GB Parity Data each
P, 7, 11 2, 6, P
Drive 3 Drive 4
250 GB 400 GB
RAID 5
B
4, P, 10 P, 8, 12
Total Unused
Space = 450 GB
Drive 5 Drive 6
400 GB 400 GB
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