[netcdfgroup] netCDF4 with HDF5 1.10

• To: "netcdfgroup@xxxxxxxxxxxxxxxx List" <netcdfgroup@xxxxxxxxxxxxxxxx>
• Subject: [netcdfgroup] netCDF4 with HDF5 1.10
• From: Ward Fisher <wfisher@xxxxxxxx>
• Date: Thu, 7 Apr 2016 11:39:42 -0600

Hello all,

With the recent release of HDF5 1.10, we wanted to make sure our community
is aware of a couple of issues currently surrounding its use with netCDF4.
First, netCDF4 files created using the HDF5 1.10 library will not be
readable by netCDF4 systems using the HDF5 1.8 library. This is a known
property of HDF5 1.10, but we want to raise awareness that if you are
creating data for distribution, you should probably stick to using the HDF5
1.8 libraries for now as they will be most broadly compatible.

Fortunately, the HDF5 1.10 library provides backwards compatibility so that
the inverse is not true; netCDF4 files generated with HDF5 1.8 are readable
by netCDF4 libraries using HDF5 1.10.

As HDF5 1.10 has only been recently released, we’re still coming up to
speed on the new features and capabilities. We’re working on adding a
special attribute to netCDF4 files which will dictate the version of
libhdf5 used to create it, so that we can use this information in future
releases, particularly if a subsequent libhdf5 changes the underlying file
format, again. Once we have a handle on this, we will begin exploring the
new features offered by HDF5 1.10 and if/how we can leverage them in a new
netCDF4 data model/file format.

I’ve created a GitHub issue to track our progress on adapting to HDF5 1.10,
viewable here:

   - https://github.com/Unidata/netcdf-c/issues/250

Thanks all,

-Ward

Ward Fisher
wfisher@xxxxxxxx
UCAR/Unidata - Software Engineer
NetCDF Team Lead
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