Why no rlogin to nodes?

[David Bremner]

Walt Dabell writes:
 > 
 > I never disabled rlogin (or ftp ot telnet for that matter) on the
 > nodes of my cluster. Now I have a user who is rlogin-ing to
 > nodes, then rlogin-ing from there to yet other nodes. Is there 
 > a reason someone would want to do this? 

Well, I am just an egg, as they say, but...

In absence of more sophisticated tools, this may be the only way to
check on the functioning of an MPI job.  I.e. the fact that one of
processes has not started or is idle can tell you a lot.  Also, if
things get badly wedged, it may be the only way to kill runaway
processes.