Re: Performance regression in IO scheduler still there

Jan Kara
2009-11-10T18:37:27Z

On Fri 06-11-09 09:14:53, Jeff Moyer wrote:
> Corrado Zoccolo <czoccolo@gmail.com> writes:
>
> > Hi Jeff,
> > what hardware are you using for tests?
> > I see aggregated random read bandwidth is larger than sequential read
> > bandwidth, and write bandwidth greater than read.
> > Is this a SAN with multiple independent spindles?
>
> Yeah, this is a single path to an HP EVA storage array. There are 24 or
> so disks striped in the pool used to create the volume I am using. Jan,
> could you repeat your tests with /sys/block/sdX/queue/iosched/low_latency
> set to 0?
I'll give it a spin tomorrow...

Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR