[OMPI users] Problem with Mellanox device selection

Hi everyone, I have a cluster of 32 nodes with Infiniband, four of them additionally have a 10G Mellanox Ethernet card for faster I/O. If my job based on openmpi 1.10.6 ends up on one of these nodes, it will crash: No OpenFabrics connection schemes reported that they were able to be used on a

[OMPI users] OpenMPI & Slurm: mpiexec/mpirun vs. srun

Greeting OpenMPI users and devs! We use OpenMPI with Slurm as our scheduler, and a user has asked me this: should they use mpiexec/mpirun or srun to start their MPI jobs through Slurm? My inclination is to use mpiexec, since that is the only method that's (somewhat) defined in the MPI

Re: [OMPI users] OpenMPI & Slurm: mpiexec/mpirun vs. srun

We have had reports of applications running faster when executing under OMPI’s mpiexec versus when started by srun. Reasons aren’t entirely clear, but are likely related to differences in mapping/binding options (OMPI provides a very large range compared to srun) and optimization flags provided