[MITgcm-support] gluemnc

[John Pender]

Hi All-
I have a question about gluemnc.  I have been getting netcdf output from MITgcm for a long time, which has been working fine with output data and with the grid files.  I run in multiprocessor mode so there is a netcdf output file for each tile and I glob them together using gluemnc.  This works great on smaller grids (240x200 by 100 layers) but I've started with a much denser grid (1200x1000 by 100 layers) and suddenly - for the grid file - every single 2D field (drC, Depth, etc) is missing in the resulting grid.glob.nc file though the 1D fields ( RC, drF, etc) show up fine.  The computer here (pacman at ARSC) has a couple options for the nco module

nco/4.3.0.gnu-4.7.3(default)
nco/4.3.1.gnu-4.7.3 

and I get the same problem either way.  All the way at the end of the log file for the gluemnc run for the grid I see some new error messages alluding to large file size, which is exactly my problem.  There is also a mention of the distinction between netcdf3 and netcdf4 but I've been assuming MITgcm used netcdf4 by default.

…
ERROR NC_EVARSIZE One or more variable sizes violate format constraints
HINT: NC_EVARSIZE errors can occur when attempting to aggregate netCDF3
classic files together into outputs that exceed the capacity of the netCDF3
classic file format, e.g., a variable with size in excess of 2^31 bytes.
In this case, try altering the output file type to netCDF3 classic with 64-bit offsets (with --64)
or to netCDF4 (with -4). For more details, see http://nco.sf.net/nco.html#fl_fmt
...

The total size of the grid material is about 3GB.

I'm hoping others have run into this and there's a simple fix, but I'm psychologically prepared for the worst.

Thanks very much,

John
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mitgcm.org/pipermail/mitgcm-support/attachments/20140619/9d650cb4/attachment.htm>