[Beowulf] ssh authenticity issue

[Mark Hahn]

> I wanted to carry out a test of parallel installation of a molecular
> dynamics program (amber) operating directly on the parallel computer
> (the ssh daemon was stopped)

eh?  I don't see that it _ever_ makes sense to stop sshd.

> The command (as user)
>
> make test < /dev/null
>
> asked to confirm the RSA key fingerprint, unable to establish the
> authenticity of the host (the same computer). I entered NO in the fear
> of overwriting pub keys (please see below the reason).

"unable to establish" means that the ssh client did not find the host's
ssh key in either your ~/.ssh/know_hosts or /etc/ssh/ssh_known_hosts.
you should simply add it to the latter.

> by the router). I must add that the computing machine at issue knows
> itself through the keys, i.e., if i type
>
> ssh computername date

but you didn't show the literal ssh command that "make test" is triggering.
for instance, it might be "ssh localhost", and that alias for computername
might not be in the known_hosts files.

> the date is obtained passwordless (this is needed by one of
> computational programs which needs this feature for its
> parallelization and it is a feature destroyed by overwritings).

I don't understand this "overwriting" thing.  known_hosts should 
always contain correct info.  using a different name for the same 
computer won't overwrite anything.