[netCDF #GXY-620794]: nf_open_par() Unknown file format

So it turns out that that file you sent me (iconR2B04-grid.nc)
is actually a netcdf-3 file with 64bit offset. Reading it will not
use HDF5 at all. You can read it in using mpio by using the 
NC_PNETCDF flag when opening the file. That also requires that you
build the netcdf library with pnetcdf enabled. The pnetcdf library
in turn used mpio.
BTW, to see the file format use this command:
    ncdump -k iconR2B04-grid.nc


> ...Just in case there is another problem with my email
> attachment, you may download the file here:
> 
> http://www.performancejones.com/iconR2B04-grid.nc.gz
> 
> I have tested this just to be sure.
> 
> 
> On Tue, Aug 28, 2018 at 08:22:30AM +0000, Max R. Dechantsreiter wrote:
> > On Mon, Aug 27, 2018 at 01:33:22PM -0600, Unidata netCDF Support wrote:
> > > I saw no email attachment. All I saw was this:
> >
> > OK, for the fourth time I am attaching the file.
> > It is possible your mail and mine (Mutt) are not plauying nice,
> > so please check the size of the message - including attachment
> > it should be several MB.
> >
> > My original inquiry, including test program, is below.
> >
> >
> > > Dear NetCDF Support:
> > >
> > > I have an input file that I can read with my ncdump, open
> > > with nf_open(), but which gives an error with nf_open_par():
> > >
> > > Testing nf_open()...
> > >
> > > nf_open():
> > > No error
> > >
> > > nf_close():
> > > No error
> > >
> > > Testing nf_open_par()...
> > >
> > > nf_open_par():
> > > NetCDF: Unknown file format
> > >
> > > What does this mean - what is it about the file that that
> > > allows it to be opened by nf_open() but not nf_open_par()?
> > > I get the same error with different versions of NetCDF,
> > > and with different versions of HDF5 (if that matters).
> > >
> > > Below is my test script.
> > >
> > > Best regards,
> > >
> > > Max
> > > ---
> > > Max R. Dechantsreiter
> > > President
> > > Performance Jones L.L.C.
> > > address@hidden
> > >
> > >
> > > #!/bin/sh
> > >
> > > cat > test_nf_open_par.F90 << EOF
> > > program test_nf_open_par
> > > !USE mpi, ONLY: MPI_INFO_NULL
> > > USE mpi
> > > INCLUDE 'netcdf.inc'
> > >
> > > character (len=*), parameter :: grid="iconR2B04-grid.nc"
> > > integer :: ierr, ncid, status
> > >
> > > call MPI_Init(ierr)
> > >
> > > print '()'
> > >
> > > print '(a,/)', "Testing nf_open()..."
> > > status = nf_open(grid, nf_nowrite, ncid)
> > > print *, "nf_open(): ", nf_strerror(status)
> > > if (status == nf_noerr) then
> > > status = nf_close(ncid)
> > > print *, "nf_close(): ", nf_strerror(status)
> > > end if
> > >
> > > print '(a,/)', "Testing nf_open_par()..."
> > > status = nf_open_par(grid, IOR(nf_nowrite, nf_mpiio), &
> > > &                        MPI_COMM_WORLD, MPI_INFO_NULL, ncid)
> > > print *, "nf_open_par(): ", nf_strerror(status)
> > > if (status == nf_noerr) then
> > > status = nf_close(ncid)
> > > print *, "nf_close(): ", nf_strerror(status)
> > > end if
> > >
> > > call MPI_Finalize(ierr)
> > >
> > > end program test_nf_open_par
> > > EOF
> > >
> > > module purge
> > > module load intel/2017.5.239
> > > module load impi/2017.4.239
> > > module list
> > >
> > > ZLIB_VERSION=1.2.11
> > > SZIP_VERSION=2.1.1
> > > HDF5_VERSION=1.10.2
> > > HDF5_VERSION=1.8.18
> > > NETCDF_C_VERSION=4.6.1
> > > NETCDF_FORTRAN_VERSION=4.4.4
> > >
> > > LIB=/global/scratch/users/maxd/ICON/lib-avx512
> > >
> > > ZLIB=$LIB/zlib-$ZLIB_VERSION
> > > SZLIB=$LIB/szip-$SZIP_VERSION
> > > HDF5=$LIB/phdf5-$HDF5_VERSION
> > > NETCDF4=$LIB/netCDF4-$NETCDF_C_VERSION
> > >
> > > export 
> > > CPATH=$NETCDF4/include:$HDF5/include:$ZLIB/include:$SZLIB/include:$CPATH
> > > LD_LIBRARY_PATH=$HDF5/lib:$ZLIB/lib:$SZLIB/lib:$LD_LIBRARY_PATH
> > > LD_LIBRARY_PATH=$NETCDF4/lib:$LD_LIBRARY_PATH
> > > LIBRARY_PATH=$LD_LIBRARY_PATH
> > > export LD_LIBRARY_PATH # shared libraries
> > > export LIBRARY_PATH    # static libraries
> > >
> > > mpiifort test_nf_open_par.F90 -lnetcdff -lnetcdf -lhdf5 -lsz -lz
> > >
> > > mpiexec -n 1 ./a.out
> 
> 
> 

=Dennis Heimbigner
  Unidata


Ticket Details
===================
Ticket ID: GXY-620794
Department: Support netCDF
Priority: Normal
Status: Open
===================
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