Building NetCDF-4 with Parallel I/O

21.4 Building NetCDF-4 with Parallel I/O

You must build netCDF-4 properly to take advantage of parallel features.

HDF5 must be built with --enable-parallel.
Typically the CC environment variable is set to mpicc, and the FC to mpifc (or some local variant.) You must build HDF5 and netCDF-4 with the same compiler and compiler options.
The netCDF configure script will detect the parallel capability of HDF5 and build the netCDF-4 parallel I/O features automatically. No configure options to the netcdf configure are required.
For parallel builds you must include "netcdf_par.h" before (or instead of) netcdf.h.
Parallel tests are run by shell scripts (ex. nf_test/run_f77_par_test.sh). For testing to work on your platform the mpiexec utility must be supported.
Parallel I/O is tested in nc_test4/tst_parallel.c, nc_test4/tst_parallel2.c, and nc_test4/tst_parallel3.c, and other programs, if the --enable-parallel-tests option to configure is used.
Fortran 90 parallel tests are run in nf_test directory: f90tst_parallel, f90tst_parallel2, f90tst_parallel3, f90tst_nc4_par1, f90tst_nc4_par.

The parallel test nc_test4/tst_nc4perf was written to help NASA GMAO test performance. It's output can tell you a lot about your parallel platform.