Chris, Can you try to
mpirun --mca io romio314 ... And see if it helps ? Cheers, Gilles Christopher Brady <c.s.br...@warwick.ac.uk> wrote: >I have been working with a Fortran code that has to write a large array to >disk excluding an outer strip of guard cells using MPI-IO. This uses two MPI >types, one representing an array the size of the main array without its guard >cells that is passed to MPI_File_set_view as the filetype, and another that >represents the subsection of the main array not including the guard cells that >is used as the datatype in MPI_File_write (same result with >MPI_File_write_all). Both subarrays are created using >MPI_Type_create_subarray. When the file size (per core) reaches a value of >512MB the final output size diverges from the expected one and is always >smaller than expected. It does not reach a hard bound, but is always smaller >than expected. I have replicated this behaviour on machines using Open-MPI >2.1.2 and 3.0.0, and am attaching a simple test code (in both C and "use mpi" >Fortran) that replicates the behaviour on a single core (the test codes only >work on a single core, but I have demonstra ted the same problem on multiple cores with our main code). While I've replicated this behaviour on several machines (every machine that I've tried it on), I'm also attaching the ompi_info output and config.log files for a machine that demonstrates the problem. > >If anyone can tell me if I've made a mistake, if this is a known bug that I've >missed in the archives (very sorry if so), or even if this is a previously >unknown bug I'd be very grateful. > >Many Thanks >Chris Brady >Senior Research Software Engineer >University of Warwick > _______________________________________________ users mailing list users@lists.open-mpi.org https://lists.open-mpi.org/mailman/listinfo/users
