[Beowulf] Restricting users from ssh into nodes

[Mark Hahn]

> 1. Many people's job scripts use ssh either directly (to say clean up /tmp)
> or indirectly from mpirun.

sure.

> (good mpirun's use the batch engine's per-node
> daemon to launch the binaries not ssh).

why should a scheduler have daemons cluttering up compute nodes?
also, do you really launch so many very big but very short jobs 
that startup time is a serious concern?  I'm questioning assumptions here.

thanks, mark.