PnetCDF

PnetCDF source code development repository

PnetCDF is a parallel I/O library for accessing Unidata's NetCDF files in classic formats. The software development is a collaborative work of Northwestern University and Argonne National Laboratory.

• The original repository: https://svn.mcs.anl.gov/repos/parallel-netcdf
• Since June 1, 2018, the PnetCDF repository has been migrated to here on github.

PnetCDF project home page

• https://parallel-netcdf.github.io contains more information about PnetCDF.

PnetCDF official software releases

• The alpha release of 1.15.0 is available on October 27, 2025.
• The latest stable release is pnetcdf-1.14.1.tar.gz (release note), available since July 31, 2025.
• All official released versions can be found in https://parallel-netcdf.github.io/wiki/Download.html
• Note the "releases" link on this page above contains only tagged versions. They are by no means official releases, but simply checkpoints. They contain unused historical files. Users are recommended to download the official releases, not tagged versions.

Build PnetCDF using source codes of this development repository

• The source codes in this repository are constantly under development. They should NOT be used for production runs.
• Building PnetCDF using the source codes in this repository only if you are interested in contributing the project and we welcome and appreciate any contribution.
• Required software
  • MPI compilers, e.g. MPICH and OpenMPI
  • autoconfig version 2.71
  • automake version 1.16.5
  • libtool version 2.5.4
  • m4 version 1.4.17
• Clone, build, and installation commands:

  git clone https://github.com/Parallel-NetCDF/PnetCDF.git
  
  cd PnetCDF
  autoreconf -i
  
  ./configure --prefix=/install/path --with-mpi=/mpi/path
  make install
  

Build instructions and recipes

• Please read file INSTALL for build instructions. There are also several build recipes under folder doc for a few popular systems.

Users documents

• C API references
• Questions & Answers
• Utility Programs
• NetCDF4 vs. PnetCDF
• PnetCDF blocking vs. non-blocking APIs
• CDL header API references

Mailing List

• parallel-netcdf@mcs.anl.gov
  • To subscribe, please visit the list information page https://lists.mcs.anl.gov/mailman/listinfo/parallel-netcdf
  • The past discussions in the mailing list are available in: http://lists.mcs.anl.gov/pipermail/parallel-netcdf/.

External links to some related projects and application users

• PnetCDF Python, a python interface to PnetCDF library.
• E3SM I/O kernel study
• Scorpio, the I/O module of E3SM.
• PIO - parallel I/O library at NCAR.
• WRF - Weather Research & Forecasting Model at NCAR.

Acknowledgements

• Ongoing development and maintenance of PnetCDF-python is supported by the U.S. Department of Energy's Office of Science, Scientific Discovery through Advanced Computing (SciDAC) program, OASIS Institute.
• From 2016 to 2023, the development and maintenance of PnetCDF was supported by the Exascale Computing Project (17-SC-20-SC), a joint project of the U.S. Department of Energy's Office of Science and National Nuclear Security Administration, responsible for delivering a capable exascale ecosystem, including software, applications, and hardware technology, to support the nation's exascale computing imperative.
• The PnetCDF project has been continuously supported by the U.S. Department of Energy's Office of Science, Scientific Discovery through Advanced Computing (SciDAC) program since its initiation in 2001.