Hi Loris, That depends on how Slurm is configured on your side. If you have Slurm installed with the pmix plugin (`srun --mpi=list`), then "--with-slurm" and "--with-pmi" are indeed not needed with modern OpenMPI. It will use PMIx to communicate with Slurm. This is the default in Easybuild for OpenMPI v4.
If your installation of Slurm only has the pmi2 plugin or you want to install old versions of OpenMPI, then you need to enable "--with-slurm" and "--with-pmi". Kind regards, Alex Domingo HPC Team VUB - Informatie & Communicatietechnologie Pleinlaan 9 - 1050 Brussel https://hpc.vub.be ________________________________________ From: [email protected] <[email protected]> on behalf of Loris Bennett <[email protected]> Sent: Wednesday, 2 February 2022 14:39 To: easybuild Subject: [easybuild] OpenMPI: --with-slurm needed or not Hi, While searching again for stuff to alleviate my recurring confusion about OpenMPI, PMIx and Slurm, I can across the following posting from myself: https://www.mail-archive.com/[email protected]/msg05468.html In it I asked with reference to building OpenMPI with --with-slurm: It seems to me that '--with-slurm' is not needed at all, since this has been the default at least as far back as OpenMPI 1.0.1. So following Åke's argument in the discussion in the link, wouldn't it be better to change the comments in the OpenMPI ECs to just: # to enable PMI integration (site-specific) # configopts = '--with-pmi' ? Back then no-one responded and the thread died. However, the following https://www.open-mpi.org/faq/?category=building#build-rte seems to support the idea that --with-slurm is not needed. So should the comment in the OpenMPI EC be changed? Cheers, Loris -- Dr. Loris Bennett (Herr/Mr) ZEDAT, Freie Universität Berlin Email [email protected]
