"-N 1" restricts a job to a single node. We've continued to have issues with this. Historically we've had a single partition with multiple generations of nodes segregated for multinode scheduling via topology.conf. "Use -N 1" (unless you really know what you're doing) only goes so far.
There are a few other things that we may address in a submission plugin, and this will be added. As previously mentioned, the other approach is to have a partition limited to single-node scheduling (as the default partition), and advise users who really know how to do multi-node process management (MPI or other) to use an overlapping partition. On Fri, May 8, 2020 at 4:10 PM Michael Robbert <mrobb...@mines.edu> wrote: > Manuel, > > You may want to instruct your users to use ‘-c’ or ‘—cpus-per-task’ to > define the number of cpus that they need. Please correct me if I’m wrong, > but I believe that will restrict the jobs to a singe node whereas ‘-n’ or > ‘—ntasks’ is really for multi process jobs which can be spread amongst > multiple nodes. > > > > Mike > > > > *From: *slurm-users <slurm-users-boun...@lists.schedmd.com> on behalf of > "Holtgrewe, Manuel" <manuel.holtgr...@bihealth.de> > *Reply-To: *Slurm User Community List <slurm-users@lists.schedmd.com> > *Date: *Friday, May 8, 2020 at 03:28 > *To: *"slurm-users@lists.schedmd.com" <slurm-users@lists.schedmd.com> > *Subject: *[External] [slurm-users] Defining a default --nodes=1 > > > > *CAUTION:* This email originated from outside of the Colorado School of > Mines organization. Do not click on links or open attachments unless you > recognize the sender and know the content is safe. > > > > Dear all, > > > > we're running a cluster where the large majority of jobs will use > multi-threading and no message passing. Sometimes CPU>1 jobs are scheduled > to run on more than one node (which would be fine for MPI jobs of course...) > > > > Is it possible to automatically set "--nodes=1" for all jobs outside of > the "mpi" partition (that we setup for message passing jobs)? > > > > Thank you, > > Manuel > > > > -- > Dr. Manuel Holtgrewe, Dipl.-Inform. > Bioinformatician > Core Unit Bioinformatics – CUBI > Berlin Institute of Health / Max Delbrück Center for Molecular Medicine in > the Helmholtz Association / Charité – Universitätsmedizin Berlin > > Visiting Address: Invalidenstr. 80, 3rd Floor, Room 03 028, 10117 Berlin > Postal Address: Chariteplatz 1, 10117 Berlin > > E-Mail: manuel.holtgr...@bihealth.de > Phone: +49 30 450 543 607 > Fax: +49 30 450 7 543 901 > Web: cubi.bihealth.org www.bihealth.org www.mdc-berlin.de > www.charite.de >
