The parallel-netcdf (formerly "pnetcdf") package from Argonne and
Northwestern can be used for parallel I/O with classic netCDF data.
For classic and 64-bit offset formats parallel I/O can be obtained
with parallel-netcdf, the parallel netCDF package from Argonne and
Northwestern.
Parallel NetCDF is not a Unidata product, but it is well-tested and
maintained. See
the pNetCDF
web page for more information.
Parallel netCDF uses MPI I/O to perform parallel I/O. It is a complete
rewrite of the core C library using MPI I/O instead of POSIX.
Unfortunately the parallel netCDF package implements a different
API from the netCDF API, making portability with other netCDF code a
problem.
Fortunately, netCDF-4 can now use the parallel netCDF library to
access classic and 64-bit offset files using parallel I/O, just as
if they were HDF5/NetCDF-4 files.
Use the NC_PNETCDF flag to achieve this. This is tested in
nc_test4/tst_parallel2.c.
if (nc_create_par(file_name, NC_PNETCDF, comm, info, &ncid)) ERR;
