Hints on improving performance with WRF and Pnetcdf

[Rob Latham]

On Sun, Sep 05, 2010 at 09:01:03AM -0500, Gerry Creager wrote:
> Rob Latham wrote:
> >I know ranger's running openmpi, but can you give mpich2 a shot?  i
> >only ask because recent mpich2 releases have an optimized lustre
> >driver for collective i/o.
> 
> I'll see what we have. I've tried to use other mpich variants before...

OK.  I think the only version of MPICH2 with the debugged and
optimized Lustre driver is MPICH2-1.3.1 (currently "beta" released,
with a release candidate due "any day now").    So, if you don't mind
building from source, try MPICH2-1.3b1. 

Other mpich and mpich2 variants (Mvapich v1, mvapich v2) either don't
have the optimized driver, or the version they do have is buggy.

Wei-keng's library, though, *is* optimized and debugged, and as long
as you get the link order right, should give you good lustre
performance.  I'm going to go pick up that discussion on another
thread.

==rob

-- 
Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA