I thought it might be nice to recap the characteristics of the possible RAID
configurations.
Please feel free to correct any points that are incorrect or inaccurate.
I was thinking of comparing the characteristics of various RAID configurations
using 4 250G disks.
(4) Disk RAID1:
Total Array Capacity: 250G
Reading Throughput: <= 4 x a single drive read cap.
1 file can be read simultaneous 4 times
or 4 separate file can be read simultaneously
Write Throughput: <= a single drive write cap.
Fault tolerance: can survive 3 disk failures
(4) Disk RAID0:
Total Array Capacity: 1000G
Reading Throughput: <<= 4 x a single drive read cap.
1 file can be read at-most 1 time
or 4 separate file can be read simultaneously
Write Throughput: <= 4 x a single drive write cap.
Fault tolerance: can survive 0 disk failures
(4) Disk RAID5:
Total Array Capacity: 750G
Reading Throughput: <= 2 x a single drive read cap. (similar to RAID0)
1 file can be read at-most 1 time
or 4 separate file can be read simultaneously
Write Throughput: <= 1 x a single drive write cap.
Fault tolerance: can survive 1 disk failures
(4) Disk RAID10 --Layout=n(near):
functions similar to a RAID1&0 but more closely
follows the pattern of a RAID1 i.e. better read preformance
than write preformance
Total Array Capacity: 500G
Reading Throughput: <= 4 x a single drive read cap. (similar to RAID0)
1 file can be read at-most 2 times
or 4 separate file can be read simultaneously
Write Throughput: <= 2 x a single drive write cap.
Fault tolerance: can survive at most 2 disk failures
(4) Disk RAID10 --Layout=o(offset):
functions similar to a RAID1&0 but more closely
follows the pattern of a RAID0 i.e. better write preformance
than read preformance
Total Array Capacity: 500G
Reading Throughput: <= 4 x a single drive read cap. (similar to RAID0)
1 file can be read at-most 2 times
or 4 separate file can be read simultaneously
Write Throughput: <= 2 x a single drive write cap.
Fault tolerance: can survive at most 2 disk failures
(4) Disk RAID10 --Layout=f(far):
functions similar to a RAID1&0 but more closely
follows the pattern of a RAID1 i.e. better read preformance
than write preformance
I am not sure sure how this differs from
--Layout=n(near)
Total Array Capacity: 500G
Reading Throughput: <= 4 x a single drive read cap. (similar to RAID0)
1 file can be read at-most 2 times
or 4 separate file can be read simultaneously
Write Throughput: <= 2 x a single drive write cap.
Fault tolerance: can survive at most 2 disk failures
Regards,
Richard Broersma Jr.
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