[Lustre-discuss] read performance on ia64

[Michel Dionne]

The sgi has 256 dual core 1.6Ghz cpus.

The write performance is up to 375MB/s on a single dd using 1 core and
writing on a folder with lfs setstripe of 4.
It is only on read that the cpu usage of this one core limits reads to
142MB/s. This core is busy with ptlrpcd during the read.
Is version v1_8_0_RC2 production ready or should we wait?

Thanks

Michel

-----Original Message-----
From: Andreas.Dilger at sun.com [mailto:Andreas.Dilger at sun.com] On Behalf
Of Andreas Dilger
Sent: March 6, 2009 05:07
To: Michel Dionne
Cc: lustre-discuss at lists.lustre.org
Subject: Re: [Lustre-discuss] read performance on ia64

On Mar 04, 2009  14:53 -0500, Michel Dionne wrote:
> I am running test between an X4150 and SGI Altix with luster 1.6.6 and
I
> can see a read performance drop on the SGI.

How many cores on the SGI system?

> Numbers:
> X4150
> dd if=/dev/zero of=/mnt/exec4_client_ib/mike/4/bigfile bs=4096k
> count=10000 (336MB/s) this a folder with a stripe of 4 for all tests
> dd if=/mnt/exec4_client_ib/mike/4/bigfile of=/dev/null bs=4096k
> (461MB/s)
> 
> SGI Altix
> dd if=/dev/zero of=/mnt/exec4_client_ib/mike/4/bigfile bs=4096k
> count=2000 (371MB/s) 99% of the core is running dd
> dd if=/mnt/exec4_client_ib/mike/4/bigfile of=/dev/null bs=4096k
> (142MB/s) 20% is running dd and 80% is running ptlrpcd
> 
> 
> The X4140 is running:
> 2.6.18-92.1.10.el5_lustre.1.6.6smp #1 SMP Tue Aug 26 12:16:17 EDT 2008
> x86_64 x86_64 x86_64 GNU/Linux
> Red Hat Enterprise Linux Server release 5.2 (Tikanga)
> 
> The SGI is running:
> SGI Altix systems 2.6.16.46-0.12-default #1 SMP Thu May 17 14:00:09
UTC 
> 2007	4 ia64 ia64 GNU/Linux

Please try running the v1_8_0_RC2 from CVS - it has patches that should
improve the scalability of the client when there are many CPUs.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.