On Mar 2, 2014, at 3:46 PM, Gustavo Correa <[email protected]> wrote:

Not trying to hijack Ron's thread (he has more important hurdles to get behind him), I wonder how mpiexec (Hydra), which is launched on one computer under one user name, will trigger additional MPI processes on the other computers under different user names (and how ssh may have to be setup to allow this to happen).

mpiexec launches additional helper processes (proxy) on each “node”. The helper processes can be of any user id. “Node” is just a domain that is controlled by one proxy. The user can treat a single physical nodes as multiple “nodes” in Hydra’s terminology by using different entries in the host file to specify each of them. — Pavan