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Subject: Re: [OMPI users] openmpi/openib problems
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2008-02-21 20:00:46


On Feb 20, 2008, at 9:53 AM, jessie puls wrote:

> Secifically Jobs are not being handed to other nodes ever. Running
>
> mpirun -mca btl openib,self -np 20 /bin/hostname
>
> will return the same hostname 20 times, even if I specify -bynode as
> an argument.

This is normal, and not an InfiniBand issue. You need to tell Open
MPI where to run your jobs (i.e., which hosts). If you don't, Open
MPI assumes you want to run on the localhost.

A simple way to specify where to run is to use a hostfile:

http://www.open-mpi.org/faq/?category=running#run-prereqs
http://www.open-mpi.org/faq/?category=running#simple-launch
http://www.open-mpi.org/faq/?category=running#simple-spmd-run

-- 
Jeff Squyres
Cisco Systems