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Re: 980218: netcdf-3.3.1 parallel version for T3E

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  • Subject: Re: 980218: netcdf-3.3.1 parallel version for T3E
  • Date: Thu, 19 Feb 1998 13:15:10 -0700
>cc: Harsh Anand <address@hidden>
>From: Harsh Anand <address@hidden>
>Subject: netcdf-3.3.1 parallel version for T3E
>Organization: LBNL/NERSC
>Keywords: 199802190147.SAA16417 netCDF 3.3.1 parallel T3E
>
> Hi,
>
> I have recently installed netcdf-3.3.1 serial version
> on T3E.  I understand you are working on the parallel
> version. Could you please let me know its status?

Netcdf-3 is currently not "MP safe". The design is such
that it is easier to make safe, but without more agreement
from vendors on lock calls and low level parallel i/o calls
we have not made it a high priority.

Most of the demand seems to for the T3E, so, given appropriate
collaboration, that it probably the platform where we would first
do it.

> BTW, I ran the following simple parallel test case
> with the serial version and it gave correct results.
>
>
> Can we use this serial version to do parallel I/O
> with netCDF files? How about the performance?

You can use netcdf in parallel applications, but it
would be safest to have all netcdf library calls to a given
file occur serially on a single processor.

> Thanks.
>
> Harsh Anand
> (510) 486-5575

You are welcome.

-glenn