Dell PERC 6/i RAID Performance Testing

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We recently received a new Dell R710
with a PERC 6/i RAID controller and six 15k SAS drives. I have been doing some
performance testing using hdparm and seeker on two different configurations and I'm not
quite sure what to make of the
results.

Configurations:

6
Disk RAID 10 - 64k stripe - Write through, no read ahead - RHEL
5.5

Results:

Timing buffered disk reads: 1024 MB in 3.01
seconds = 340.69 MB/sec

Results: 206
seeks/second, 4.848 ms random access time (137662331 < offsets <
436165962118)

4 Disk RAID 10, RAID 1
for OS - 64k stripe - Write through, no read ahead - RHEL
5.5

Timing buffered disk reads: 956 MB
in 3.01 seconds = 318.13
MB/sec

Results: 209 seeks/second,
4.771 ms random access time (58179688 < offsets <
292314580383)

My first
question is whether these results are within the expected range for our hardware. Using
a RAID
calculator it seems that I should be able to get higher speeds out of either
configuration.

Also, while the first
configuration performs slightly better, the second configuration would allow us to
separate our MySQL databases from and isolate other IO to the RAID 1. I feel like that
isolation would prove more beneficial than a few more
MB/s.

Thoughts? Any input is
appreciated.

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class="normal">Answer

Yeah. You TOTALLY focus on the wront number. Nothing cares about MB/s on a
server. The ONLY relevant item is IOPS. Because moves destroy
IO.

Make a check that checks random IO of
appropriate size for your database server. Because most of the time you will have
various processes hit the discs with different requests, so it is purely
random.

So, what IOPS numbers di you
have?