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>To: address@hidden >cc: Bjarne B?chmann <address@hidden>, >cc: Peter Gylling J?rgensen <address@hidden> >From: Karsten Bolding <address@hidden> >Subject: restoring headers in large netcdf files >Organization: Bolding & Burchard Hydrodynamics >Keywords: 200502190949.j1J9ncv2029855 netCDF large file header restore Hi Karsten, Way back on 22 Feb, I wrote: > Then run > > ncgen -b large.cdl; ls -l large.nc > > For me this took a little over 3 minutes to produce a file over 3 GiB > in size: > > -rw-r--r-- 1 russ ustaff 3221225648 Feb 22 16:47 large.nc > > Now this is a CDF1 (classic) netCDF file, so even older versions of > NCO should be able to handle it, as long as NCO is built with large > file system support. If you attempt the NCO operation > > ncks -v time large.nc > > I would think it should work, if NCO is built with large file support. > But I don't have NCO built with large file support to try this with > right now. The version I have from 2003 gives what looks like an > unrelated error: > > $ /scratch/russ/nco-2.7.1/bin/ncks -v time large.nc time.nc > ncks: ERROR unable to determine method for remote retrieval of large.nc > > I will try to build a version of nco with large file support and try > this out to make sure it works as it should, or if not to report it as > an nco bug. Unfortunately, I ran into an NCO build bug that I couldn't find a workaround for, and it may be a few days before it gets resolved. An NCO developer wrote me: > ... This is a known problem and I had nailed it on the Opteron and > was verifying it and getting the build to work smoothly on my laptop > when I realized I no longer had your email. > > I'll try to get it nailed down today, but we just lost the dual > Opteron server where most of my code changes were (and weren't > committed to CVS yet...). We have to send it out to get its > motherboard replaced - the data's safe, just not available for a few > days (I hope). But I kept notes on my laptop so I should be able to > run thru them pretty fast (knock wood). So I can't yet verify that the current NCO, compiled with large file support or as a 64-bit executable, will handle a large CDF1 file, but I still believe it should. I'll let you know what I find out ... --Russ _____________________________________________________________________ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu/staff/russ