[mpich-discuss] Starting processes in root on multiple machines

[Gus Correa]

On 06/19/2013 08:14 AM, Pavan Balaji wrote:
>
> On 06/19/2013 05:13 AM, Lee, Eibhlin wrote:
>> Jim and Pavan will be glad to hear I have now switched to Hydra. I am
>> able to run cpi as user on multiple machines. I am also able to run cpi
>> as root on one machine. However, I am having difficulty setting up ssh
>> properly so that I can run cpi as root on multiple machines.
>
> Excellent. Once you login as root, can you ssh into the other nodes?
> You'll need to set that up first.
>
>> How can I force a process to run as root on another machine?
>
> Once the above ssh is setup, you don't need to do anything special. Just
> login as root and run your application.
>
> -- Pavan
>

I would caution that passwordless ssh for root is not a secure thing.
It may be alright if you keep your cluster off the Internet.
Maybe the cluster is dedicated to run the MPI A/D converter program?

Some people/sites disable remote root logins
(or any direct root logins).
So, Eibhlin may want to check if any of these restrictive mechanisms
exist in his cluster's nodes:
http://www.centos.org/docs/4/4.5/Security_Guide/s2-wstation-privileges-noroot.html

I hope this helps,
Gus Correa