installation help needed ...newbie

Donald Becker becker at
Fri Mar 8 16:03:44 PST 2002

On Fri, 8 Mar 2002, Stephanie Bluebear wrote:

> This is the deal. We have a cluster with 16 nodes (32
> proc) running scyld. However, I need redhat 7.2 for an
> application that I will be using.

What aspect of Red Hat 7.2 do you need?  Our upcoming release will have
a 2.4 kernel, updated glibc, XFree 4, etc. but few applications should
depend on these updates.

> a new cluster running rh7.2. I removed three nodes
> from the existing cluster to do this. All three have
> the same configuration.

> I installed redhat 7.2 on all three machines. Assigned
> them hostnames of alpha, beta and gamma.
> I set up ethernet such that their IP addresses were 
> alpha:
> beta :
> gamma:
> (they are connected through a linksys switch, btw)
> using netconfig, I added hosts (beta and gamma to
> alpha),  (alpha and gamma to beta) and (alpha and beta
> to gamma) on all three machines. I guess this in
> essence adds those hosts to /etc/hosts. I also added 
> /etc/hosts.equiv files to include all three machine
> names.
> I can ping all the machines from every other machine. 
> However, I can not rsh from one machine to another.
> e.g., from alpha, typing "rsh beta ls" does nothing. I
> can see the machnines trying to communicate via the
> blinking LED s in the switch, but nothing happens on
> the screen.
> What could be the possible reasons? 

With 'rsh' there are many opportunities for permission problems.
Are you trying to run 'rsh' as root, or as a regular user?
Do you have the same set of users on all machines?
Do you have a ~root/.rhosts files as well as /etc/hosts.equiv?
(And there is probably something in the new xinetd that could cause
problems as well.)

I perceive that the community consensus is that 'ssh' should replace
'rsh'.  It has substantially more start-up overhead, but handles the
environment much better.  It would be possible (and easier) to improve
'rsh', but people seem to feel that it's flaws are fixed-in-stone

For your case, 'ssh' is clear about how you failed authentication.

> Any help would be appreciated. I  have spent three
> frustrating days trying to figure this out to no
> avail.

[ Not quite surpressed ....

Donald Becker				becker at
Scyld Computing Corporation
410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
Annapolis MD 21403			410-990-9993

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