[Lustre-discuss] read performance on ia64

[Michel Dionne]

Hello all

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.

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

cat /etc/issue
Welcome to SUSE Linux Enterprise Server 10 SP1 (ia64)

We compiled lustre 1.6.6 on the SGI  and everything works but the read
performance is slowed down by the ptlrpcd.

What should we look at to fix.

Thanks

Michel