Computer Science 400 Parallel Processing Siena College Fall 2008

Everyone needs to get familiar with the cluster system right away. This "0^th" lab, due at the end of our class meeting, is intended to speed that process. Please feel free to ask if anything is unclear or is giving you trouble.

Here's what to do:

1. See Dr. Teresco to create your account and to receive your initial password. This account works only on our cluster and is independent of any accounts you have on other systems.
2. Log in to your account. You will connect with Secure Shell (ssh) from any computer within the School of Science network. Any computer in a lab on the third floor of Roger Bacon will do.
   • From Windows, you can use putty. From a Mac or Linux (preferred), open a terminal window and run the ssh command.
   • The hostname for the head node of the cluster is sccluster.teresco.org. This name exists globally, but is meaningful only within the School of Science network.
   • This computer is running the FreeBSD operating system. It is intended to be the primary login node and compiling node for FreeBSD executions.
   • From inside the cluster, this machine is known as head, since it is the "head node" of our cluster.
3. Once logged in, change your password to something you can remember with the passwd command.
4. Next, we set up your account to allow you to log in to the other nodes of the cluster from head without having to type a password every time.
   1. Generate a public/private DSA key pair with the command:

      ssh-keygen -t dsa
      

      You can safely accept all of the defaults when prompted during the execution of this command.
   2. Copy the public key to your authorized keys file with the following command:

      cp .ssh/id_dsa.pub .ssh/authorized_keys2
      

5. Log into each node of the cluster.
   • You can find a list of nodes on the cluster in the file /cluster/nodes. The command

     cat /cluster/nodes
     

     will show you the contents of this file. Some of these nodes run FreeBSD, others run Solaris.
   • Use the command ssh to connect to a cluster node. For example, to connect to bullpen, you will issue the command:

     ssh bullpen
     

   • The first time you log in to any node, you will probably see a message asking if you wish to accept the identity of the remote host. You can safely answer "yes".
   • On each node, run the command uname to see if it is a FreeBSD or a Solaris (SunOS) system.
   • To log out of a node and return to your session on the head node, you can either type logout or hit Ctrl-d.
6. Run a simple C program. There is a "hello, world" program in the class shared area.
   1. Copy the program to your account:

      cp ~terescoj/shared/cs400/examples/hello/hello.c .
      

   2. Compile the program to an executable named hello:

      gcc -o hello hello.c
      

   3. Run the program:

      ./hello
      

   4. Run the program again, this time redirecting its output to the file hello.txt:

      ./hello > hello.txt
      

7. Finally, make sure that you can submit work using the cluster's "turnin" system. Here, you will be submitting the file hello.txt that you created in the previous step. You will be using a similar procedure for subsequent submissions.
   1. Set up your "turnin" area for the submission of Lab 0:

      turnin setup lab0
      

      You should see several messages, the last of which tells you the next step:
   2. Place the files you wish to submit (in this case, just the hello.txt file) into your lab 0 turnin directory:

      cp hello.txt ~/turnin/400/lab0
      

   3. Submit the file to the turnin system:

      turnin submit lab0
      

      You should again see a few messages, the last of which is something like "Committed revision 5."