Greetings Neil.
In addition to what George and Mitch said:
Open MPI will not require a full set of daemons like LAM/MPI does. You
can have a full set if you wish, especially in environments where it
makes sense (e.g., rsh/ssh, where there is little other infrastructure
to do proper distributed process control). There will be helper
commands analogous to lamboot/lamhalt to help launch/kill these
daemons.
For other environments, you can simply mpirun directly. Unlike LAM,
mpirun has the capability to talk to PBS (for example), rather than
lamboot.
1) Is Open MPI thread-safe (assuming the system-supplied libraries are
thread-safe)? In particular will it be possible to call MPI routines
from OpenMP regions and will it be possible to use OpenMP directives
within MPI tasks?
2) Does Open MPI use the same mechanism as LAM-MPI's "lamboot"
(rsh/ssh) to start daemons on other nodes or is there a different
mechanism altogether?
--
{+} Jeff Squyres
{+} The Open MPI Project
{+} http://www.open-mpi.org/
