This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
Hi Lin, > I have a problem associated with netcdf file size. I already set supporting > large file in environment variables,"setenv WRFIO_NCD_LARGE_FILE_SUPPORT 1". > But, it still has problem when writing a file as large as 30G. So, is the > netcdf do not permit to write a file to 30G? NetCDF can support writing files larger than 30GB. For details, see this set of questions and answers: http://www.unidata.ucar.edu/software/netcdf/docs/faq.html#Large%20File%20Support There have been a few bug fixes related to large files in previous versions of netCDF software, described in the RELEASE_NOTES file that is included with each new version, for example: release notes for version 4.2.1-rc1: http://www.unidata.ucar.edu/software/netcdf/release-notes-4.2.1-rc1.html has this: Fixed bug in 64-bit offset files with large records, when last record variable requires more than 2**32 bytes per record. [NCF-164] with a link to more information about the fix in the "[NCF-164]" link: https://www.unidata.ucar.edu/jira/browse/NCF-164 Other similar fixes in recent versions are described briefly and then in more detail in these links: Version 4.2.0: http://www.unidata.ucar.edu/software/netcdf/release-notes-4.2.html Fixed problem with 64-bit offset format where writing more than 2**31 records resulted in erroneous NC_EINVALCOORDS error. [NCF-101] https://www.unidata.ucar.edu/jira/browse/NCF-101 Dimension size in classic model netCDF-4 files now allows larger sizes than allowed for 64-bit offset classic files. [NCF-117] https://www.unidata.ucar.edu/jira/browse/NCF-117 Version 4.1.2: Fixed two large-file bugs with using classic format or 64-bit offset format and accessing multidimensional variables with more than 2**32 values. (No detailed description available ...) From the information you provided, I can't tell if any of the above bug fixes are relevant to the problem you are seeing, but if you could provide a small program that can be used to reproduce the problem, we can test it against the current software release to see if it still occurs. It may also be a problem with WRF configuration, but for that, you would have to contact WRF support ... --Russ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: SOA-856908 Department: Support netCDF Priority: Normal Status: Closed