[Gluster-users] Major performance problem with WRF

[Anand Avati]

>>> We are attempting to run WRF to a shared glusterfs filesystem.  It is
>>> not going well at all.  WRF does a bunch of fseeks as well as writes and
>>> I'm seeing at least a 30:1 slowdown between accessing the underlying
>>> filesystem vs going through glusterfs.  A coworker has written a trivial
>>> test program that implements this sort of access pattern.  Currently
>>> using the 1.4.0rc7 version.

It is an unfair to compare clustered filesystems and local disk
filesystems directly. You can try a few optimizations - the io-threads
is pretty much useless on the client side in 1.4/2.0 branch (since the
introduction of non blocking sockets). You can remove read-ahead too
since I understand your IO pattern largely involves random IO, and for
sequential IO glusterfs can achieve link max speed on Gig/E even
without read-ahead. After these changes you might also want to try
with and without write-behind because these performance translators
are meant to be used with streaming IO.

Do you have a comparison against NFS? (since you are using glusterfs
in a single server mode anyways). Can you also post the test program
which simulates your work load?

Thanks,
avati