Rolf Vandevaart <rolf.vandeva...@sun.com> writes: >> However, I found that if I explicitly specify the "-machinefile >> $TMPDIR/machines", all 8 mpi processes were spawned within a single >> node, i.e. node0002.
I had that sort of behaviour recently when the tight integration was broken on the installation we'd been given, and it took me a long time to spot. [Is the orte_leave_session_attached fix relevant here?] > And for what it is worth, as you have seen, > you do not need to specify a machines file. Open MPI will use the > ones that were allocated by SGE. Yes, but there's a problem with the recommended (as far as I remember) setup, with one slot per node to ensure a single job per node. In that case, you have no control over allocation -- -bynode and -byslot are equivalent, which apparently can badly affect some codes. We're currently using a starter to generate a hosts file for that reason (complicated by having dual- and quad-core nodes) and would welcome a better idea.
