[Stgt-devel] Different throughput numbers on SLES 10 and RHEL 5.1
Wed May 14 10:26:00 CEST 2008
On Sun, Mar 2, 2008 at 11:50 AM, Erez Zilber <erezz at voltaire.com> wrote:
> Mike Christie wrote:
> > Erez Zilber wrote:
> >> Hi,
> >> I'm using the latest stgt release (tgt-20071227) and I see different
> >> throughput numbers for READ commands on SLES 10 & RHEL 5.1. I'm using
> >> stgt with iSCSI over iSER.
> >> I'm using the same initiator (open-iscsi 865.15 from OFED 1.3 rc4) and
> >> the same target machine. The target machine has 2 partitions - one is
> >> SLES 10 & the other is RHEL 5.1. When I run READ commands against the
> >> target on SLES 10, I get ~400 MB/sec (which is the throughput of the
> >> LUN). When I run the same READ commands from the same initiator against
> >> the target on RHEL 5.1, I get only 240 MB/sec.
> >> Is there anything that I need to config on the RHEL 5.1 machine? BTW -
> >> if I run the same test directly from the target machine, I get 400
> >> MB/sec on both distros.
> >> Here's the command that I use:
> >> sgp_dd if=/dev/sdc of=/dev/null bs=512 bpt=1024 thr=8 time=1
> >> count=20480000
> > Does this command try to keep 8 IOs running in parrallel, and if so
> > did you try the noop scheduler (I think for SG_IO this will not make a
> > difference)?
> I tried noop & cfq, but didn't see any dramatic change. BTW -
> if=/dev/sg3 (not /dev/sdc), so the command that I'm running is:
> sgp_dd if=/dev/sg3 of=/dev/null bs=512 bpt=1024 thr=8 time=1 count=20480000
> > Is the target by any chance running on a x86_64 box?
> Yes. Which box are you using? BTW - our non-stgt target is also running
> on a x86_64 box successfully.
Do you have any update (other ideas) on this issue?
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