Cluster Access

NOTE: Starting September 1st, 2017 users who connect to Learning Applications and Technologies’ Linux Cluster while off campus will need to install and use the VPN "AnyConnect" client application prior to using Linux Cluster. This change is an added security measure for those accessing resources on the Linux Cluster from outside the Penn State campus.  

The VPN AnyConnect client is available at downloads.its.psu.edu under "Connecting to Penn State." Instructions for installing VPN AnyConnect are available at http://kb.its.psu.edu/article/891

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There are a few methods to access the linux cluster.  There is the non-graphical method using an SSH client to connect from your local machine to the linux cluster.  This method is for those who are comfortable with the command-line or do not need a graphical user interface (GUI) to interact with the system.  The other method to access the linux cluster is to use a GUI via a X11. This method is for users who are more comfortable with graphical environments similar to Windows or Mac OS X.  Here are some diretions to get you started with accessing the Linux Cluster from various operatings systems.

Getting Started

To access the linux cluster using any method you need a SSH client.  For Mac OS X and Linux, an SSH client is built in to the operating system.  On a Mac, you can access SSH from the Terminal application located in the Utilities folder.  On Linux, you can access SSH using the directions below.  For the Windows operating systems, you can download you can download SSH clients from http://downloads.its.psu.edu and navigate to the 'File Transfer' section to download the appropriate client.  Once you have an SSH client, you are ready to connect to the Linux Cluster.  

Non-graphical SSH

Linux

If you are connecting to the cluster from Linux/Unix and are using a command line ssh client, just type "ssh <PSUid>@lxcluster.tlt.psu.edu" where <PSUid> is your Penn State User Id. If you have not ssh'ed to the cluster from that machine before you will get a message stating that the authenticity of the host cannot be established, it will give you an RSA key, and ask if you want to continue. Type 'yes' to continue, and then enter your password when it prompts you for it.

Windows

There are several ssh clients for Windows such as PuTTY (a Google seach will lead to this download).  If you are using PuTTY for Windows, start the application.  Under Session, enter the hostname you want to connect to: lxcluster.tlt.psu.edu on port 22.  Make sure the connection type is ssh.  Click Open to bring up the terminal and login using your psuid/password.

Mac OS X

If you are using Mac OS X, start the Terminal.app application by going to the Finder -> Applications -> Utilities -> Terminal. Once the terminal window comes up, type "ssh <PSUid>@lxcluster.tlt.psu.edu" where <PSUid> is your Penn State User ID. If you have not ssh'ed to the cluster from that machine before you will get a message stating that the authenticity of the host cannot be established, it will give you an RSA key, and ask if you want to continue. Type 'yes' to continue, and then enter your password when it prompts you for it.

Graphical SSH

Linux

If you are using a fairly recent version of a more popular distribution of linux (Red Hat, Fedora, Suse, Debian, etc.) then you shouldn't need any special software. Since you are using linux, you most llikely already have X windows running. If you don't have a graphical login then you'll need to start the X Windows system, but this is not the normal setup for a desktop linux machine. The only change you might have to make, is when connecting to the cluster, use the command "ssh -Y <PSUid>@lxcluster.tlt.psu.edu". The -Y option enables trusted X11 forwarding. This means that X11 will be forwarded to your screen and not subjected to the X11 security extention controls. For more information type "man ssh" on your linux console.

Windows

In order to display graphical applications from the cluster on a windows PC, you need to have an X windows environment. This is different from Microsoft's "Windows" Operating system. The most common way to do this is to download and install Xming. Xming is a PC X Window Server. This enables programs being run remotely to be displayed on your desktop. It can found at http://sourceforge.net/projects/xming/ .  Use it along with PuTTY to connect to the Linux Cluster.  

To install and configure Xming, do the following:

  1. Navigate to http://sourceforge.net/projects/xming/ and download Xming and Xming-fonts.
  2. By default both programs will be installed into the same location, so don't the worry about over writing files. We cannot work without both packages.
  3. Once installed, running All Programs > Xming > XLaunch is a good idea to see what the configuration looks like. In most cases, the default options should be just fine.
  4. Finally run All Programs > Xming > Xming to start the PC X Server. The “X” icon should be visible on the Windows TaskbarThe X Server must be started before setting up a SSH connection to the Linux Cluster.

Next, we need to configure PuTTY to use the X11 environment by doing the following:

  1. Launch PuTTY.
  2. Under Session, enter the hostname you want to connect to: lxcluster.tlt.psu.edu on port 22.  Make sure the connection type is ssh.
  3. Next, scroll to Connection > SSH > X11. Check the box next to Enable X11 Forwarding. By default the X Display location is empty. You can enter localhost:0. The remote authentication should be set to MIT-Magic-Cookie-1
  4. Finally go back to Session. You can save your session too, and load it each time you want to connect.
  5. Click Open to bring up the terminal and login using your psuid/password
  6. Open a graphical application by typing in the command name (i.e. xchat)

PuTTY Configuration for GUI via X11

Mac OS X

In order to display graphical applications from the cluster in Mac OS X, you need to have an X windows environment. This is different from Mac OS X GUI environment. The most common way to do this is to download and install XQuartz. XQuartz project is an open-source effort to develop a version of the X.Org X Window System that runs on OS X. This enables programs being run remotely to be displayed on your desktop. It can found at http://www.xquartz.org.  Use it to connect to the Linux Cluster.

To install and use XQuartz, do the following:

  1. Navigate to http://www.xquartz.org and download the latest release of Quartz.
  2. Run the XQuartz installer.  Once installed, the program can be found at Applications -> Utilities -> XQuartz
  3. At the terninal window, ssh to the cluster by typing "ssh -Y <PSUid>@lxcluster.tlt.psu.edu" where <PSUid> is your PSU ID.  Then enter your password.
  4. Once you have logged in, open a graphical application by typing in the application name (i.e. xchat) at the command prompt.

Contact Us:

If you experience any problems in trying to access the cluster, please submit a help request.

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Last Updated August 21, 2017