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Subject: Re: [OMPI users] SLURM and OpenMPI
From: Werner Augustin (Werner.Augustin_at_[hidden])
Date: 2008-03-27 08:41:52


On Fri, 21 Mar 2008 17:41:28 -0400
"Sacerdoti, Federico" <Federico.Sacerdoti_at_[hidden]> wrote:

> Ralph, we wrote a launcher for mvapich that uses srun to launch but
> keeps tight control of where processes are started. The way we did it
> was to force srun to launch a single process on a particular node.
>
> The launcher calls many of these:
> srun --jobid $JOBID -N 1 -n 1 -w host005 CMD ARGS

My work-around will be an mpirun which looks something like this:

#!/bin/bash

hostfile=`mktemp` || exit 1

srun /bin/hostname | sort | uniq -c | sed -e 's/ *\([0-9]\+\) \+\(.\+\)/\2 slots=\1/' > $hostfile

/usr/bin/mpirun.openmpi-1.2.4 --hostfile $hostfile $@
rm $hostfile

i.e. we are collecting all nodes with "srun /bin/hostname", sort and
count them and bring them into the format of a hostfile:

node001 slots=4
node002 slots=2
...

But that's definitely not the API to slurm, Ralph was talking about :-)

Werner