Reto, I should have also pointed out that the output of the program you attached was *** SUCCESS writing example file simple_xy_par.nc! even if I commented out the line that forced independent writes by calling nf90_var_par_access(ncid, varid, nf90_independent) Also, for your information, another user has recently reported a bug in the implementation of nf90_var_par_access when used with parallel-netcdf: http://www.unidata.ucar.edu/support/help/MailArchives/netcdf/msg11678.html --Russ > Sorry to have taken so long to respond to your question. > > I have been using NetCDF-4 Parallel I/O with the Fortran 90 interface for > > some time with success. Thank you for this great tool! > > > > However, I now have an issue with independent access: > > > > - NetCDF F90 Parallel access (NetCDF-4, MPIIO) > > - 3 fixed and 1 unlimited dimension > > - alle processes open/close the file and write metadata > > - only a few processes write to the file (-> independent access) > > - the write hangs. It works fine if all processes take place. > > > > I've changed your example F90 parallel I/O file simple_xy_par_wr.f90 to > > include a unlimited dimension and independent access of only a subset of > > processes. Same issue. Even if I explicitly set the access type to > > independent for the variable. Can you reproduce the issue on your side? > > > > The following system configuration on my side: > > - NetCDF 126.96.36.199 and F90 interface 4.2 > > - hdf5 1.8.9 > > - Openmpi 1. > > - OSX, gcc 4.6.3 > > No, I haven't been able to reproduce the issue, but I can't exactly duplicate > your configuration easily, and there have been some updates and bug fixes that > may have made a difference. > > First I tried this configuration, which worked fine on your attached example: > > - NetCDF 4.3.0-rc4 and F90 interface 4.2 > - hdf5 1.8.11 (release candidate from svn repository) > - mpich2-1.3.1 > - Linux Fedora, mpicc, mpif90 wrapping gcc, gfortran 4.5.1 > > So if you can build those versions, it should work for you. I'm not sure > whether > the fix is in netCDF-4.3.0 or in hdf5-1.8.11, but both have a fix for at > least one > parallel I/O hanging process issue: > > https://bugtracking.unidata.ucar.edu/browse/NCF-214 (fix in netCDF-4.3.0) > https://bugtracking.unidata.ucar.edu/browse/NCF-240 (fix in HDF5-1.8.11) > > --Russ > > Russ Rew UCAR Unidata Program > address@hidden http://www.unidata.ucar.edu > > Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: TIR-820282 Department: Support netCDF Priority: High Status: Closed
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