[Beowulf] Node not answering...

[Mark Hahn]

> mpirun: cannot start a.out on n1: No such file or directory
...
> As you can see, node "n1" is not answering. Any ideas about how to solve this 
> issue?

the first step is always to just turn on "verbose" switches
(to mpirun, in this case).  either the spawning method (mpd?  ssh?)
is failing, or something at a lower level (such as the executable
or cwd not being accessible because of a failed mount.)