Section: 12.4 Parallel I/O in NetCDF-4

12.4 Parallel I/O in NetCDF-4

NetCDF-4 exposes the parallel I/O features of HDF5.

HDF5 provides easy-to-use parallel I/O feature.
On systems which support MPI/IO, and which built HDF5 parallel I/O features, netCDF will build with parallel I/O features by default.
Special nc_create_par and nc_open_par functions are used to create/open a netCDF file. The files they open are normal NetCDF-4/HDF5 files, but these functions also take MPI paramters.
Parallel I/O is tested in nc_test4/tst_parallel.c, nc_test4/tst_parallel2.c, and nc_test4/tst_parallel3.c.
It's not very clear how to test this on every parallel system, so the --disable-parallel-tests flag is provided to configure to turn off tests of parallel I/O.