title: What command does MPI run over SSH?
body: <p>I have OpenMPI installed and I'm running a script on multiple nodes with mpiexec. OpenMPI requires that the node I'm running the mpiexec command on have SSH access to the other nodes in the cluster.</p>
  
  <p>What specifically does OpenMPI do over SSH to start the processes on the other nodes? It runs my MPI script, sure, but how does MPI run in such that each node is assigned a rank, for example?</p>
  
  <p>Thank you.</p>