PE2950, LSI SAS -> SATA very slow
linux-poweredge.lists at tisc.de
Tue May 4 03:58:58 CDT 2010
On Tue, May 04, 2010 at 10:32:25AM +1000, Adam Nielsen wrote:
> > 10MB/sec does seem extremely poor. we've had read slowness when Linux block
> > device read-ahead was too small. Once properly configured, performance on
> > RAID-5 went from 150MB/sec to 500MB/sec, so the difference is dramatic. we
> > usually tune read-ahead (in Linux) buffers starting from 8MB to 32MB and
> > benchmark to see what works best. but your problem may be elsewhere... we've
> > never seen 10MB/sec...
> Have you got any pointers to where this can be adjusted? It seems
> (according to Google) there are countless methods and patches, most of
> which are for rather old kernel versions.
blockdev --setra blocks /dev/sda
It is part of util-linux-ng .
"What we nourish flourishes." - "Was wir nähren erblüht."
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