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Re: netcdf help

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  • Subject: Re: netcdf help
  • Date: Sat, 08 Sep 2001 11:43:13 -0600
>To: address@hidden
>From: "Alan S. Dawes" <address@hidden>
>Subject: Re: 20010808: large file support in netCDF 3.5.0
>Organization: UCAR/Unidata
>Keywords: 200108082235.f78MZM110902, huge files, large file support, record

Alan,

> I have sussed how to do large dumps on an IBM
> running AIX 4.3 + 32bit and 64bit platforms. So
> hold your horses. I will send you a detailed email
> with my solutions next week.

That's great, I'll be curious to hear about it.  I had figured out
what the problem was here before I got your message and managed to
create a large ( > 5 Gbyte before I ran out of disk space) netCDF file
with the sample Fortran program you sent.

It turns out that the C library must be compiled with the -DNDEBUG
flag in order to permit writing large files, because of an incorrect
assert() statement left in for debugging purposes at line 277 of
libsrc/posixio.c:

        assert(offset < X_INT_MAX); /* sanity check */

Compiling with -DNDEBUG turns off assertion checking and allows large
files to be written.  

It should not be necessary to compile with -DNDEBUG to read and write
large files, so we'll find and fix all occurrences of these too-srict
assertions before releasing netCDF 3.5.1.

--Russ