Writing large files from pnetcdf on IBM

[Robert Latham]

On Tue, Nov 28, 2006 at 12:20:06PM -0700, John Michalakes wrote:
> If I keep the NF_64BIT_OFFSET flag and write the file that is < 2GB, I get:
> 
> 0000000  4344 4601 0000 0001 0000 000a 0000 0008
> 0000020  0000 0004 5469 6d65 0000 0000 0000 000a
> 0000040  4461 7465 5374 724c 656e 0000 0000 0013
> 
> Which is correct, but it's still CDF1, even though the flag is set in the
> NFMPI_CREATE.
> 
> BTW, if I use serial NetCDF to write the >2GB file with NF_64BIT_OFFSET:
> 
> 0000000  4344 4602 0000 0000 0000 000a 0000 0008
> 0000020  0000 0004 5469 6d65 0000 0000 0000 000a
> 0000040  4461 7465 5374 724c 656e 0000 0000 0013
> 
> but it is *very* slow.
> 
> Without NF_64BIT_OFFSET, serial NetCDF fails trying to open the file.

Ok, this is good information, especially that the NF_64BIT_OFFSET flag
is not creating CDF-2 files.  I will have to dig into this.  I'll send
an update when I know more...

==rob

-- 
Rob Latham
Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
Argonne National Lab, IL USA                 B29D F333 664A 4280 315B