Hoffman2:Accessing the Cluster

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Here are some of our favorite ways to access the Hoffman2 Cluster login nodes.

SSH - Command Line

The official description of how to do this is found here

SSH stands for Secure Shell and is a method of remotely logging into a computer using an encrypted connection. It is a command line tool and is available on most *nix-based operating systems with ports available for Windows.

If you are on a Mac or a PC running Linux/Unix...

1. Open up X11 or Terminal. Both are under Applications > Utilities on Macs.
2. Type the command

   $ ssh -X [USERNAME]@hoffman2.idre.ucla.edu

   filling in your Hoffman2 username.

   The -X is for X11 Forwarding so that any graphics that are rendered on Hoffman2 get forwarded to the screen of your computer. A -Y flag accomplishes the same thing but does not secure the connection. Correct us if we have that switched.

3. Press enter and type in your password when it asks for it. No characters or asterisks will show up while you type.
4. Provided your typing was good, you will be greeted by the Hoffman2 login message and have successfully SSHd into a login node.

If you are on a PC running Windows...

1. Go here and follow the instructions under From a PC running Windows. We recommend PuTTY or NX Client.
2. Once you have that setup, the process is the same as if you were on a Mac or Linux/Unix machine

NX Client - GUI

The official description of how to do this is found here

The NX Client program allows you to set up a Virtual Network Computing (VNC)-like session with Hoffman2. This session will keep running even if your Internet connection drops in and out (much like screen on the command line).

1. Go to the No Machine website and navigate to the Download tab.
2. Find the section titled NX Client Products and click on the one for the operating system you are running.

   NOTE: If you are running OS X 10.7 Lion or 10.8 Mountain Lion, only NX Client 4.x will work for your operating system. As of March 2012, this version of NX Client was still in testing but could be downloaded in the Download Preview section of the website ([1]).

3. Download the appropriate installation file and install it on your computer.
4. Once it is installed on your computer, start up NX Client.
5. The window that appears will ask for:
   • Login -- your Hoffman2 username
   • Password -- your Hoffman2 password
   • Session -- type Hoffman2
6. Then click the Configure... button and fill out the necessary information
   • Under the General tab
     • In the Server section
       • Host -- hoffman2.idre.ucla.edu
       • Port -- 22
       • Key -- Click this button and delete the contents of the window that appears. Open up an SSH session to Hoffman2 and run the command

         $ cat /etc/nxserver/client.id_dsa.key

         The output is the key. Copy everything that was printed out and paste it into the Key window in NX Client and click Save.

     • In the Desktop section -- Use the drop down menus to select Unix and GNOME
   • Click Save
7. Now you can click Login on the main window and a GUI environment connection will be established with a Hoffman2 login node.

Troubleshooting

If your NX Client session freezes and you are unable to close it properly, open NX Session Administrator and disconnect your session from there. This freezing often occurs when your Internet connection is lost abruptly.

UCLA Grid Portal

The official description of how to do this is found here

We haven't used this one much yet, but we'll be trying it out and get back to you about our experiences.

External Links

• Accessing Hoffman2 via Command Line
• Accessing Hoffman2 via NX Client
• Information about Hoffman2 Login Nodes -- RSA Fingerprints, node addresses
• Accessing Hoffman2 through UCLA Grid Portal