Accessing Athena

From athena

The Athena computational resource is managed by the PACS group and staff at CENPA.

Contents

[edit] To obtain an account:

  1. Generate an SSH key pair if you do not already have one. Please see the SSH tutorial for help on generating SSH key pairs.
  2. Email help@phys.washington.edu an request an account, making sure to include in the email your public SSH key. You will not be given a password, but will login to the system using your SSH keypair.
  3. Once you account has been created, you may login to the to the head node: athena0.npl.washington.edu.
  4. After you log in, read the rest of the documentation on the Athena Wiki. If you have any further questions, please email help@phys.washington.edu

[edit] IMPORTANT Accessing Athena from outside Physics, Astronomy and CENPA:

For security reasons, the Athena cluster is accessible from Physics, INT, Astronomy, and CENPA system only! So be sure to log into a system from one of these entities before ssh'ing to the head node, athena0.npl.washington.edu. You will need to either have your private SSH key installed on the Physics/INT/Astro/CENPA system, or you will have to use ssh-agent with agent forwarding enabled at every step from your local system to Athena. Details for both of these options are given below.

[edit] Installing private key on a departmental system

If you followed the tutorial at SSH Keys, you will have generated a keypair. Make sure that the private key generated from this pair is resident at ~/.ssh/id_rsa (or ~/.ssh/id_dsa if you used a DSA key) on the departmental system. It will also need to have the correct permissions as detailed below: 

 % ls -al ~/.ssh
 drwx------   2 gardnerj gardnerj  4096 Mar  3 19:05 ./
 drwxr-xr-x 107 gardnerj gardnerj 20480 Aug  6 15:04 ../
 -rw-------   1 gardnerj gardnerj  1672 Nov 18  2008 id_rsa

If these permissions are not as shown, then do 

 % chmod 600 ~/.ssh/id_rsa

[edit] SSH agent forwarding to Athena

SSH Agents are incredibly useful. The provide almost the same convenience as passwordless keypair login, but with the security keypairs with passphrases. Inasmuch as it minimizes the number of systems that your private key is stored on, it may even provide better security than straight keypairs with passphrases. To learn about SSH agents, read the tutorial on SSH Keys.

Once you have executed ssh-add on your local system, login to the departmental machine using ssh -A, which forces your agent to be forwarded (note: the departmental system must be configured also accept your public key, by having it in ~/.ssh/authorized_keys). Then ssh -A athena0.npl.washington.edu and you should be able to login to Athena.