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

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.

Mac/Linux/Unix

Simple SSH

Use the ssh command from a terminal:

ssh login_id@hoffman2.idre.ucla.edu

where login_id is replaced by your cluster user name.

GUI-Enabled SSH [Recommended]

Macs (post - Snow Leopard 10.6.x) no longer come with a X Window System Server pre-installed.

Before doing the following steps, please install XQuartz and restart your computer.

For more information about XQuartz, read here.

1. Open up X11/XQuartz 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.

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 SSH into a login node.

Windows

1. Go here and follow the instructions under Windows. We recommend PuTTY or Cgywin.
2. Once you have that setup, the process is the same as if you were on a Mac or Linux/Unix machine
3. TODO: [More information Coming]

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).

Mac OS X 10.7+ / Windows / Linux

What You Need

1. Go to the No Machine website (No Machine) and download/install the No Machine for Mac OS X/Windows/Linux.
2. Hoffman2 NX Client Public Key
   • To get the NX Client Public Key, follow the steps below or email support@ccn.ucla.edu
     • (OSX/Linux) Open up a Terminal and run the following command (replacing USERNAME with your Hoffman2 username)

       $ scp USERNAME@hoffman2.idre.ucla.edu:/etc/nxserver/client.id_dsa.key ~/Documents/

     • (Windows) Use a sftp program and download the file /etc/nxserver/client.id_dsa.key on Hoffman2 (hoffman2.idre.ucla.edu)

Setup

1. Open up No Machine in Application/Desktop and Click Continue.
2. A window titled "New Connection" will appear. Fill out the fields accordingly
   • Protocol -- SSH
   • Host -- "hoffman2.idre.ucla.edu"
   • Port -- 22

1. • Select "Use the NoMachine login"
   • Select Alternate Server Key and (...) - and find the file (client.id_dsa.key) you downloaded earlier (in your Documents folder).
   • Don't use a proxy
   • Name -- Something like "Hoffman2"

1. Double click on the connection you just created (it should be the only one in the list).
2. Enter your Hoffman2 username and password and click "OK" (You may also check the box labeled "Save this setting in the configuration file" to avoid retyping this in the future)
3. Select "Create a new session". or "New Virtual Desktop"
4. In the next menu, select Create new GNOME virtual desktop.
5. A virtual desktop should appear!

Reconnections in this client are not currently supported for Hoffman2, so please make sure to logout and close your connections properly. [1]

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. Another possible cause for freezing is scrolling on certain Windows touchpads.

For more Information [Hoffman2 NX Client]

Change Passwords

Once you've logged on and made sure its works, you can change your password to something more rememberable To change passwords, logon and type:

passwd

It should ask you for your old password and then new ones.

External Links

• Hoffman2 Access
• Hoffman2 via NX Client
• Historical Notes