[MPICH] MPICH2 and PVFS2

[Robert Latham]

On Thu, Apr 12, 2007 at 11:51:27PM -0400, Peter Diamessis wrote:
> Apparently, MPICH v1.2.7..15 is still being used at the cluster. Our system
> manager has made an effort to build it to make ROMIO compatible with
> PVFS2. Nonetheless, my problems persist. Would it simply be a better
> idea that they shift the whole cluster to MPICH2, which I assume is more
> naturally compatible with PVFS2 ?

Hi Peter

First, I'm glad you're using MPI-IO to its full potential and seeing
good results.  

Second, yes, the PVFS v2 support in MPICH 1.2.7 is quite old: about 2
years of bugfixes have gone into MPICH2-1.0.5p4.  It'd be great if you
could run MPICH2 -- you might still find bugs but particularly for
noncontiguous I/O we have fixed a number of issues.  

Now, complicating the matter is that v1.2.7..15 is a version of MPICH
for the myrinet interconnect.  Your admin will know know if you are
using GM or MX.  Let your administrator know you can build MPICH2 with
gm support by configuring MPICH2 with the --with-device=ch3:nemesis:gm
flag.  You might also need --with-gm-include=/path/to/include/gm  if
your GM headers are in a different location.

> Sorry if I sound too ignorant but my I/O troubles have driven me up the 
> wall.

This is not an ignorant question at all.  Thanks for sending in the
report instead of just quitting in frustration.

==rob

-- 
Rob Latham
Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
Argonne National Lab, IL USA                 B29D F333 664A 4280 315B