[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: large netCDF data sets

>To: address@hidden
>From: "Tom Black" <address@hidden>
>Subject: Re: 20040824: large netCDF data sets
>Organization: NOAA
>Keywords: 200408241744.i7OHiDXn015989

Hi Tom,

> I've written various files on our system that were over 10 Gb in size, 
> just not netCDF ones.  Here are the options I used during installation:
> 
> > OBJECT_MODE=64
> > CC='/bin/xlc_r -q64'
> > CPPFLAGS=-DNDEBUG
> > CFLAGS='-O -D_LARGE_FILES -O -qmaxmem=-1 -qarch=auto'
> > FC='/bin/xlf_r -q64'
> > FFLAGS='-O -qarch=auto'
> > F90='/bin/xlf90_r'
> > F90FLAGS='-O -qsuffix=f=f90 -qmaxmem=-1 -qarch=auto'
> > CXX='/bin/xlC_r -q64'
> > CXXFLAGS='-O -D_LARGE_FILES -O -qmaxmem=-1 -qarch=auto'
> > NMFLAGS='-X64'
> > ARFLAGS='-X64 cru'
> 
> I had also edited my call to nf_create in the WRF SI as you instructed, 
> i.e., fixing the 2nd argument so as to look like:
> 
> iret = nf_create('wrf_test.nc', OR(NF_CLOBBER,NF_64BIT_OFFSET), ncid)
> 
> If you have any more ideas I can try, please let me know.

I've just tried building netCDF-3.6.0-beta3 with all the above
options (except I set CXX='' since our C++ compiler is not up-to-date)
and it built OK.  Then I tried compiling the wrf_test.f file I made
available by changing its suffix to .f90 and building it with

  /bin/xlf90_r -qfixed -qsuffix=f=f90 -qmaxmem=-1 -qarch=auto -q64 -o wrf_test 
-I../include -L../lib -lnetcdf -b64 /scratch/russ/lfs-tests/wrf_test.f90

in hopes that explicitly adding the "-q64" compile flag and "-b64"
link flag might make things work.  When I run the resulting
executable, it only creates a file of about 2**30 bytes and quits with
an assertion violation in the library:

  Assertion failed: *posp == OFF_NONE || *posp == lseek(nciop->fd, 0, 
SEEK_CUR), file  posixio.c, line 210
  IOT/Abort trap(coredump)

which Ed is also seeing in his test cases on AIX.  You seem to have
gotten further than this, producing a file that's about 2**31 bytes
before getting a different error, so we can't reproduce the problem
you are seeing.  But maybe if we debug and fix this problem, which
seems to be AIX-specific, it will also fix the problem you are seeing.

I'm out of town tomorrow but hope to get back to work on this on
Monday.  Getting the Large File Support to work properly on AIX
platforms is currently my top priority ...

--Russ