RSH scaling problems...

[Greg Lindahl]

> > ssh has a mode in which it can use a high port. That's how the
> > 370-node FSL system did it in 1999. This technique also worked OK on
> > Cplant at 1200 nodes.
> 
> Greg,
> 
>    Our users who have tested ssh have told us that the wall clock
> time is much larger than if they use rsh (I'm sorry I don't have any
> numbers :) This are MPI jobs running over about 12-24 hours.
> Have you seen this?

I haven't seen it. If your jobs run that long, just about any method
of starting will be efficient enough to not increase the runtime.

-- greg