mpi - Infiniband vs. Gigabit ethernet, how do I control which is used by an MPI program

Question

I have an MPI program that runs on a computer cluster that has both ethernet and Infiniband connectivity. When I compile with mpavich2's mpicc, it automatically links to the Infiniband libraries.

Is there a way to control which network is used when compiling an mpi program?

I checked the man page for mpicc and it was not useful for this.

Answer 1

After reading about this, it seams that it depends on the MPI library used. For instance, with mvapich2 the type of interconnect is an configurable option when building the library (see the docs). For OpenMPI it appears to be a runtime option when executing mpirun (see man page of mpirun or the web docs).