Rob, 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: --with-file-system=gpfs 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 -- 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 http://science.gsfc.nasa.gov/sed/bio/matthew.thompson On 12/20/21, 10:21 AM, "Latham, Robert J." <[email protected]> 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: > > ROMIO_FSTYPE_FORCE="gpfs:" > > which we've found is useful when running with Intel MPI on our GPFS > system. Hah I had no idea anyone besides me was using this little feature. Here's a bit more information for context: https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpress3.mcs.anl.gov%2Fromio%2F2019%2F02%2F20%2Fuseful-environment-variables%2F&data=04%7C01%7Cmatthew.thompson%40nasa.gov%7Caf61122a5ef345bbbf9408d9c3cc58fd%7C7005d45845be48ae8140d43da96dd17b%7C0%7C0%7C637756104698561618%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=FwCjPxubMan1uOvKoqqNTJED0QK6q5e2cfE%2FiCxu%2F%2BE%3D&reserved=0 > 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. https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpress3.mcs.anl.gov%2Fromio%2F2014%2F06%2F12%2Fromio-and-intel-mpi%2F&data=04%7C01%7Cmatthew.thompson%40nasa.gov%7Caf61122a5ef345bbbf9408d9c3cc58fd%7C7005d45845be48ae8140d43da96dd17b%7C0%7C0%7C637756104698561618%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=ezuOrZ00lYjQ2GSxxmOiRZD8WmUfcnFO99Qp7w%2BcTSI%3D&reserved=0 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: `--with-file-system=ufs+testfs+gpfs+lustre+panfs+pvfs2+unify` 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). ==rob