Justin Piszcz wrote:
> On Sat, 13 Jan 2007, Al Boldi wrote:
> > Justin Piszcz wrote:
> > > Btw, max sectors did improve my performance a little bit but
> > > stripe_cache+read_ahead were the main optimizations that made
> > > everything go faster by about ~1.5x. I have individual bonnie++
> > > benchmarks of [only] the max_sector_kb tests as well, it improved the
> > > times from 8min/bonnie run -> 7min 11 seconds or so, see below and
> > > then after that is what you requested.
> >
> > Can you repeat with /dev/sda only?
>
> For sda-- (is a 74GB raptor only)-- but ok.
Do you get the same results for the 150GB-raptor on sd{e,g,i,k}?
> # uptime
> 16:25:38 up 1 min, 3 users, load average: 0.23, 0.14, 0.05
> # cat /sys/block/sda/queue/max_sectors_kb
> 512
> # echo 3 > /proc/sys/vm/drop_caches
> # dd if=/dev/sda of=/dev/null bs=1M count=10240
> 10240+0 records in
> 10240+0 records out
> 10737418240 bytes (11 GB) copied, 150.891 seconds, 71.2 MB/s
> # echo 192 > /sys/block/sda/queue/max_sectors_kb
> # echo 3 > /proc/sys/vm/drop_caches
> # dd if=/dev/sda of=/dev/null bs=1M count=10240
> 10240+0 records in
> 10240+0 records out
> 10737418240 bytes (11 GB) copied, 150.192 seconds, 71.5 MB/s
> # echo 128 > /sys/block/sda/queue/max_sectors_kb
> # echo 3 > /proc/sys/vm/drop_caches
> # dd if=/dev/sda of=/dev/null bs=1M count=10240
> 10240+0 records in
> 10240+0 records out
> 10737418240 bytes (11 GB) copied, 150.15 seconds, 71.5 MB/s
>
>
> Does this show anything useful?
Probably a latency issue. md is highly latency sensitive.
What CPU type/speed do you have? Bootlog/dmesg?
Thanks!
--
Al
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