I have just installed intel-mpi 4.1.2.040 onf a cluster...
If I used mpiexec.hydra to start jobs one per node... it still spawns processes on all available resources...
mpiexec.hydra -ppn 1 hostname
on two nodes will show me 40 lines as oppose to only two expected.
I have added a file with debug info when running
I_MPI_HYDRA_DEBUG=1 mpiexec.hydra -ppn 1 hostname 2>&1 | tee debug.txt