Re: 64 bit version of large data set netCDF libs

address@hidden writes:

> Russ and Ed,
> Thanks for the help and access to 3.6.0.
> 
> I am trying to build a couple of large data sets for use in a SPEC benchmark. 
>  I will make sure that the SPEC folks know to include 3.6 (or greater) in 
> their package.
> 
> Since I am running WRF and building input and output data sets, I need a 
> 64-bit version of the library.  When I try to use the 32-bit version, I get 
> seg faults when the model itself is running out of space.  On Ed's directory 
> on bluesky is a 3.6.0 dir for the libs etc.  On the IBM, the system folks 
> maintain 64 bit versions of many of the libs for large memory access programs.
> 
> I do not know all of the subtleties required in your build, but could you 
> include the functionality of "setenv OBJECT_MODE 64" so that I can give the 
> large-model, big-data-set version of WRF a test.
> 
> Again guys, thanks very much.
> 
> Dave

Howdy Dave,

The netcdf library on bluesky in /home/bluesky/edh/netcdf-3.6.0/lib
was compiled with OBJECT_MODE=64.

While doing this I discovered some oddities in the interaction of
OBJECT_MODE=64 and the large file settings. Specifically, when I set
OBJECT_MODE=64 and the ran the configure, the autoconf macro decided
that no large file settings would be needed, though usually AIX
requires the _LARGE_FILES macro to be set.

That seemed OK, though, if OBJECT_MODE=64 told the AIX that everything
would be in the 64-bit mode, and, in effect, turn on the large files
feature without using the _LARGE_FILES macro.

Unfortunately, compiled under OBJECT_MODE=64, without the _LARGE_FILES
macro, netcdf failed our new large file test.

So, on bluesky, I left OBJECT_MODE=64, turned on the _LARGE_FILES
macro, and rebuilt netcdf. Now it passes our large file tests.

If you can link to that and try it I would be very interested to learn
the result.

I am going to look into OBJECT_MODE on the AIX platform today and try
to figure out what's going on...

Thanks!

Ed