FILL and NOFILL

[Wei-keng Liao]

Hi, John,

PnetCDF does not support fill mode. (It is on the wish list I guess.)

As pointed out from the URL in your email, enabling fill mode
requires "duplicate writes" which fill in the variables with fill
values before overwrite the variables later with user's data.
The pitfall is just poor performance.

Wei-keng

On Feb 24, 2014, at 3:36 PM, John Michalakes wrote:

> That’s good. Thanks, -John
>  
> From: parallel-netcdf-bounces at lists.mcs.anl.gov [mailto:parallel-netcdf-bounces at lists.mcs.anl.gov] On Behalf Of Jim Edwards
> Sent: Monday, February 24, 2014 1:20 PM
> To: John Michalakes
> Cc: parallel-netcdf at lists.mcs.anl.gov
> Subject: Re: FILL and NOFILL
>  
> No, pnetcdf does not use fill mode.
>  
> 
> On Mon, Feb 24, 2014 at 10:58 AM, John Michalakes <john.michalakes at noaa.gov> wrote:
> Does parallel netcdf have an equivalent to nc_set_fill?
>  
> http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-c/nc_005fset_005ffill.html
>  
> If so, what is the default mode, FILL or NOFILL , and are there performance benefits for using NOFILL as there are with serial NetCDF?  Any pitfalls?
>  
> Thanks,
>  
> John
> 
> 
> 
> --
> Jim Edwards
>