Physical Arrays And Hot Spares; Logical Drives - HP D5970A - NetServer - LCII Configuration Manual

Appendix B
Figures B-3 and B-4 are samples of Worksheets A and B for an HP NetRAID
adapter with ten physical drives, three arrays, and three logical drives. It has a
50% rebuild rate.

Physical Arrays and Hot Spares

Array 0 on Channel 0 contains three 9-GB physical drives (SCSI ID # 0,
1, 3).
Array 1 on Channel 1 contains two 4-GB physical drives (SCSI ID # 10
and 11).
Array 2 on Channel 2 contains four 4-GB physical drives (SCSI ID # 12,
13, 14, and 15).
A global hot spare is available in case a drive fails in any array. The
physical drive has SCSI ID #8 on Channel 0. The 9-GB capacity of the
global hot spare is greater than or equal to the physical capacity of the
individual physical drives in all three arrays.

Logical Drives

Logical Drive 0 is on Array 0 and does not span another array. It uses
RAID level 5 with a capacity of 18 GB. (The capacity of one physical
drive is used for parity.) Logical Drive 0 has a stripe size of 64 KB. Its
write policy is Write Through, its read policy is Adaptive Read Ahead,
and its cache policy is Cached.
Logical Drive 1 is on Array 1 and does not span another array. It uses
RAID level 1 with a capacity of 4 GB. (Mirroring uses up half the
physical capacity.) Logical Drive 0 has a stripe size of 16 KB. Its write
policy is Write Through, its read policy is Adaptive Read Ahead, and its
cache policy is Cached.
Logical Drive 2 is on Array 2 and does not span another array. It uses
RAID level 5 with a capacity of 12 MB. (The capacity of one physical
drive is used for parity.) Logical Drive 2 has a stripe size of 64 KB. Its
write policy is Write Through, its read policy is Adaptive Read Ahead,
and its cache policy is Cached.
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Worksheets