Why no rlogin to nodes?

[Michael Stein]

> Doesn't ssh have some extra overhead? I assume too that you
> were making that recommendation assuming that I was not running
> a dedicated cluster. Current and future clusters sit behind a mother
> node, future also behind a firewall. Is there an advantage to running
> ssh on such a cluster? I assume not?

We run a cluster without a firewall and use SSH extensively.  For anything
more than trivial programs you won't notice the SSH overhead.