On Wed, 18 Jul 2007, Hannes Dorbath wrote:
On 18.07.2007 12:23, Justin Piszcz wrote:
I am sure one of your questions is, well, why use SW RAID5 on the
controller? Because SW RAID5 is usually much faster than HW RAID5, at
least in my tests:
Though that's no answer to your question, I really can't confirm that. I'm
running a 3Ware 9650 with 8x 7200 SATAs in HW RAID 6. Writes are between
340-360MB/sec and reads peak at 430-450MB/sec. That seems to be the absolute
possible maximum those drives can deliver. The card even seems to do some
really smart stuff, as the read speed is in excess of the physical raw speed
of 6 drives.
You have done the usual settings, 3Ware recommends?
echo 64 > /sys/block/sda/queue/max_sectors_kb
echo 512 > /sys/block/sda/queue/nr_requests
echo "deadline" > /sys/block/sda/queue/scheduler
blockdev --setra 16384 /dev/sdX
Have you set the correct su,sw options for XFS?
--
Regards,
Hannes Dorbath
I will try these options during future testing and re-visit the speeds of
regular HW RAID5, thanks! I know they are part of the 3ware doc and I
need to re-bench with these.
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