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Subject: Re: [OMPI users] Query regarding OMPI_MCA_ns_nds_vpid env variable
From: Ashley Pittman (apittman_at_[hidden])
Date: 2008-07-11 09:32:16


On Fri, 2008-07-11 at 07:20 -0600, Ralph H Castain wrote:
> This variable is only for internal use and has no applicability to a user.
> Basically, it is used by the local daemon to tell an application process its
> rank when launched.
>
> Note that it disappears in v1.3...so I wouldn't recommend looking for it. Is
> there something you are trying to do with it?

Recently on this list I recommended somebody use it for their needs.

http://www.open-mpi.org/community/lists/users/2008/06/5983.php

> Reason I ask: some folks wanted to know things like the MPI rank prior to
> calling MPI_Init, so we added a few MPI envar's that are available from
> beginning of process execution, if that is what you are looking for.

It's also essential for Valgrind support which can use it to name
logfiles according to rank using the --log-file=valgrind.out.%
q{OMPI_MCA_ns_nds_vpid} option.

Ashley,