5. MPI libraries

There are different versions of the OpenMPI libraries installed on the cluster.

To run or compile a code that needs MPI, you must select which version you want to use. This process is managed using the spack utility: https://spack.io/

To use spack, you must first load the spack tool.

loadspack

It is then possible to list all the installed versions of MPI using

lsspack

and then, load the version of MPI that is needed

spack load mpiversion

Note that these commands must be included in the batch file from slurm to load properly MPI before running your job.