<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Are you certain you're PATH addition is correct? The "-np" flag is still present in a build of Open MPI 4.0.3 I just made, in fact:<div class=""><br class=""></div><div class=""><br class=""></div><blockquote style="margin: 0 0 0 40px; border: none; padding: 0px;" class=""><div class="">$ 4.0.3/bin/mpirun </div><div class="">--------------------------------------------------------------------------</div><div class="">mpirun could not find anything to do.</div><div class=""><br class=""></div><div class="">It is possible that you forgot to specify how many processes to run</div><div class="">via the "-np" argument.</div><div class="">--------------------------------------------------------------------------</div></blockquote><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Note that with the Slurm plugins present in your Open MPI build, there should be no need to use "-np" on the command line; the Slurm RAS plugin should pull such information from the Slurm runtime environment variables. If you do use "-np" to request more CPUs that the job was allocated, you'll receive oversubscription errors (you know, unless you include mpirun flags to allow that to happen).</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">What if you add "which mpirun" to your job script ahead of the "mpirun" command -- does it show you /scratch/manumachu/openmpi-4.0.3/OPENMPI_INSTALL/bin/mpirun?</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""><br class=""><blockquote type="cite" class="">On Apr 10, 2020, at 12:12 , Ravi Reddy Manumachu <<a href="mailto:ravi.manumachu@ucd.ie" class="">ravi.manumachu@ucd.ie</a>> wrote:<br class=""><br class=""><br class="">Dear Slurm Users,<br class=""><br class="">I am facing issues with the following combinations of OpenMPI and SLURM. I was wondering if you have faced something similar and can help me.<br class=""><br class="">OpenMPI-3.1.6 and slurm 19.05.5<br class="">OpenMPI-4.0.3 and slurm 19.05.5<br class=""><br class="">I have the OpenMPI packages configured with "--with-slurm" option and installed. <br class=""><br class=""> Configure command line: '--prefix=/home/manumachu/openmpi-4.0.3/OPENMPI_INSTALL' '--with-slurm'<br class=""> MCA ess: slurm (MCA v2.1.0, API v3.0.0, Component v4.0.3)<br class=""> MCA plm: slurm (MCA v2.1.0, API v2.0.0, Component v4.0.3)<br class=""> MCA ras: slurm (MCA v2.1.0, API v2.0.0, Component v4.0.3)<br class=""> MCA schizo: slurm (MCA v2.1.0, API v1.0.0, Component v4.0.3)<br class=""><br class="">I am executing the sbatch script shown below:<br class=""><br class="">#!/bin/bash<br class="">#SBATCH --account=xxxxx<br class="">#SBATCH --job-name=ompi4<br class="">#SBATCH --output=ompi4.out<br class="">#SBATCH --error=ompi4.err<br class="">#SBATCH --ntasks-per-node=1<br class="">#SBATCH --time=00:30:00<br class="">export PATH=/scratch/manumachu/openmpi-4.0.3/OPENMPI_INSTALL/bin:$PATH<br class="">export LD_LIBRARY_PATH=/scratch/manumachu/openmpi-4.0.3/OPENMPI_INSTALL/lib:$LD_LIBRARY_PATH<br class="">mpirun -np 4 ./bcast_timing -t 1<br class=""><br class="">No matter what option I give to mpirun, I get the following error:<br class="">mpirun: Error: unknown option "-np"<br class=""><br class="">I have used mpiexec also but received the same errors.<br class=""><br class="">To summarize, I am not able to call mpirun from a SLURM script. I can use srun but I have no idea how to pass MCA parameters I usually give to mpirun such as, "--map-by ppr:1:socket -mca pml ob1 -mca btl tcp,self -mca coll_tuned_use_dynamic_rules 1".<br class=""><br class="">Thank you for your help.<br class=""><br class="">-- <br class="">Kind Regards<br class="">Dr. Ravi Reddy Manumachu<br class="">Research Fellow, School of Computer Science, University College Dublin<br class="">Ravi Manumachu on Google Scholar, ResearchGate<br class=""></blockquote><br class=""></div></body></html>