[mpich-discuss] [EXTERNAL] Re: Issue with MPICH 4.0b1 and MPI I/O and ROMIO...maybe?
Thompson, Matt (GSFC-610.1)[SCIENCE SYSTEMS AND APPLICATIONS INC]
matthew.thompson at nasa.gov
Wed Dec 22 11:35:10 CST 2021
Thanks. So for a cluster that is mainly "regular linux" (not sure what they run for non-GPFS), GPFS, some tmpfs probably, and a whole bunch of NFS, what would recommend as a good set of filesystems? Would something like:
be enough, or once you have that flag does that do enough?
Also, I don't see --with-file-system in the configure help? Does the MPICH configure "pass down" the option to (I assume) ROMIO?
Matt Thompson, SSAI, Ld Scientific Programmer/Analyst
NASA GSFC, Global Modeling and Assimilation Office
Code 610.1, 8800 Greenbelt Rd, Greenbelt, MD 20771
Phone: 301-614-6712 Fax: 301-614-6246
On 12/20/21, 10:21 AM, "Latham, Robert J." <robl at mcs.anl.gov> wrote:
On Fri, 2021-12-17 at 19:10 +0000, Thompson, Matt (GSFC-610.1)[SCIENCE
SYSTEMS AND APPLICATIONS INC] via discuss wrote:
> MPICH Discuss,
NetCDF: Error initializing for parallel access
> I did a bit of debugging and found that the crash was due to an
> environment variable that was set because my application mistakenly
> thought I was running Intel MPI (mainly because we didn't have
> detection for MPICH, so it defaulted to our "default" on this cluster
> of Intel MPI). When it sees Intel MPI, it sets:
> which we've found is useful when running with Intel MPI on our GPFS
Hah I had no idea anyone besides me was using this little feature. Here's a bit more information for context:
> So, of course the "right" thing to do is not to set that. (Doctor, it
> hurts when I do this. So stop doing that.)
> But it got me wondering, is there perhaps a "better" way I should be
> building MPICH? Should this flag cause this sort of crash? Or does it
> mean I build MPICH/ROMIO incorrectly or incompletely (no GPFS
> support, say)?
Intel MPI has its own way of supporting extra file systems, via the "I_MPI_EXTRA_FILESYSTEM" environment variable.
I'm open to suggestions on how ROMIO should best handle this situation. You requested a file system (gpfs) that ROMIO did not support. ROMIO could fall back to "generic unix file system" but you asked explicitly for GPFS, presumably for a good reason (or in your case, by accident but ROMIO is not a mind reader...)
If you are building your own MPICH, add the `--with-file-system=...` flag. that is a '+'-delmited list of file systems. for example:
I try to build everything I can so my list is quite long. Yours will be shorter -- if you pick a file system for which you do not have development headers and libraries, your build will fail (hopefully at configure time).
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