# Netcdf large file support **URL:** \ **Category:** Hdf-forum archives\ **Created:** [February 9, 2009, 3:49am UTC](https://forum.hdfgroup.org/t/netcdf-large-file-support/1215 "2009-02-09T03:49:34Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Nikhil\_Laghave1](https://forum.hdfgroup.org/letter_avatar_proxy/v4/letter/n/3be4f8/32.png) [@Nikhil\_Laghave1](https://forum.hdfgroup.org/u/Nikhil_Laghave1)\ **Post date:** [February 9, 2009, 3:49am UTC](https://forum.hdfgroup.org/t/netcdf-large-file-support/1215/1 "2009-02-09T03:49:34Z")
Hello All, I am trying to create files larger than 2 GB using pnetcdf, but the application crashes. I understand I need to use NF\_64BIT\_OFFSET flag in the nfmpi\_create call, but I do not know how to pass this argument. This may seem a very silly question. I am sorry about that. In C I think we need to pass NC\_64BIT\_OFFSET | NC\_CLOBBER, but similar approach does not work with fortran. Can some one send me an example of the API for fortran? Right now, this is how I am making the call, which is not working.       retval = nfmpi\_create(comm, "nikhil.nc",NF\_64BIT\_OFFSET,      & info, ncid) Thanks. Regards, Nikhil > **···** > > ---------------------------------------------------------------------- > This mailing list is for HDF software users discussion. > To subscribe to this list, send a message to [hdf-forum-subscribe@hdfgroup.org](mailto:hdf-forum-subscribe@hdfgroup.org). > To unsubscribe, send a message to [hdf-forum-unsubscribe@hdfgroup.org](mailto:hdf-forum-unsubscribe@hdfgroup.org). ---
**Author:** ![robl](https://forum.hdfgroup.org/letter_avatar_proxy/v4/letter/r/e9a140/32.png) [@robl](https://forum.hdfgroup.org/u/robl)\ **Post date:** [February 9, 2009, 2:11pm UTC](https://forum.hdfgroup.org/t/netcdf-large-file-support/1215/2 "2009-02-09T14:11:12Z")
Hi Nikhil I think you probably meant this to go to the parallel-netcdf list, right? I copied both lists so people know I answered you, but let's follow up to just parallel-netcdf for the rest of this thread. I'm not a fortran guy, but what I think what you want to do is define an integer 'flags' and then add NF\_64BIT\_OFFSET and NF\_CLOBBER to that flags variable. integer flags flags = NF\_CLOBBER + NF\_64BIT\_OFFSET nfmpi\_create(comm, "foo.nc", flags, info, ncid) what does your application crash look like? I would hope that we catch invalid flags at nfmpi\_create time, and not later on. Can you 'nfmpi\_strerror' the return code? ==rob > **···** > > On Sun, Feb 08, 2009 at 09:49:38PM -0600, Nikhil Laghave wrote: > > > I am trying to create files larger than 2 GB using pnetcdf, but the > > application crashes. I understand I need to use NF\_64BIT\_OFFSET flag in the > > nfmpi\_create call, but I do not know how to pass this argument. This may seem > > a very silly question. I am sorry about that. > > > > In C I think we need to pass NC\_64BIT\_OFFSET | NC\_CLOBBER, but similar > > approach does not work with fortran. Can some one send me an example of the > > API for fortran? > > > > Right now, this is how I am making the call, which is not working. > >       retval = nfmpi\_create(comm, "nikhil.nc",NF\_64BIT\_OFFSET, > >      & info, ncid) > > -- > Rob Latham > Mathematics and Computer Science Division A215 0178 EA2D B059 8CDF > Argonne National Lab, IL USA B29D F333 664A 4280 315B > > ---------------------------------------------------------------------- > This mailing list is for HDF software users discussion. > To subscribe to this list, send a message to hdf-forum-subscribe@hdfgroup.org. > To unsubscribe, send a message to hdf-forum-unsubscribe@hdfgroup.org.