HPC MPI Exercise 1: One-Time Setup


Setting Up For Remote Processing

By default, MPI uses ssh (the Secure Shell) to launch processes on remote systems. However, we have configured MPI in the Unix Lab to use an older protocol called rsh (the Remote Shell). To set this up, you need to have a file named .rhosts in your home directory, containing the names of all the hosts in the Unix Lab. To create this file, enter the following command in your home directory:

    cp /home/cs/374/rhosts .rhosts
You can verify that this worked by entering:
    ls -al
and then using cat or less to view the contents of the file.

The rsh protocol requires that this .rhosts file be kept secure, so set its permissions so that you and only you can read or write to it, as follows:

    chmod 600 .rhosts
With that, you (and MPI) should now be able to use rsh to launch a process on any machine in the Unix Lab without entering a password!

If you look at the name of the first machine in the file, you can test things out by entering:

   rsh machineName
If all is well, you should login to that machine (or any of the machines named in .rhosts) without having to enter your password. Assuming this worked correctly, use Ctrl-d to logout and return to your own workstation before continuing. Once you can launch remote shells on Gold and Maroon lab machines without entering a password your are ready to generate an MPI hosts file.


CS > 374 > Exercises > 01 > One Time Setup


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