Disk Throughput test
Chuck Swiger
cswiger at mac.com
Thu Oct 23 18:00:22 UTC 2008
On Oct 23, 2008, at 10:50 AM, Stephen Sanders wrote:
> Good point about the RAID. It is set for RAID 5 as the data is
> supposed
> to be protected.
RAID-10 provides somewhat better data protection, but less available
space and better write performance especially for small writes. (For
big writes, RAID-5 can do OK also, but small writes tend to really
degrade RAID-5 performance, down to an order of magnitude *less*
throughput compared with a single raw drive.)
> Interestingly enough, diskinfo is telling me that the drive throughput
> is 175MB/s. I'm guessing that this means diskinfo is a mixture of
> reads
> and writes?
No, it should only be doing reads. For best-case read performance,
it's likely to be at or near:
dd if=_your_disks_ of=/dev/null bs=_raid_stripe_size_
...or adjust bs up or down by factors of 2 and benchmark.
Regards,
--
-Chuck
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