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Linux/Unix (for graphical Unix programs)

Setting up your Linux or Unix system for displaying Unix and Linux programs from CAE systems to your computer. This allows you to run Unix and Linux applications (such as ANSYS) that are unavailable on your computer, or to take advantage of the remote system's extra compute power without overloading your computer.

The combination of the X Window System and a secure shell (SSH) program means that you can run an application on one of the CAE network's Unix or Linux workstations without leaving your office. The X Window System is the most common graphical user interface for Unix and Linux systems, so if you see graphics, you almost definitely have X installed. The vast majority of Linux distributions include the necessary software on your installation media, and it's part of the default installation. Some Unix systems may not have SSH installed, so check with your vendor or at openssh.com for more information. Installing a Linux distribution on your computer, configuring X, and other such tasks are beyond the scope of this document, but you can experiment with various live CDs that won't require repartitioning or other potentially dangerous system changes such as Damn Small Linux, RipLinux, or Ubuntu if you want.

Assuming that your system has already started the X Window System, bring up a terminal (a dtterm, xterm, kterm, gnome-terminal, etc.). That should display a terminal window with a $ prompt on your display similar to the one below.

Linux ssh session

At your terminal's $ prompt, use the ssh command to log into one of the CAE network's Unix or Linux systems (click here for a list of those systems). The form of the ssh command is

ssh -X username@hostname.cae.tntech.edu

where username is your CAE username and hostname is the name of the Unix or Linux system you want to log into. The first time you try to connect to one of the CAE systems, you'll be prompted about an unrecgonized RSA key. This prompt should only happen once per CAE system, and if it happens more than once, one of the following things has happened:

  1. You've completely reinstalled your computer or your home directory on your computer, causing it to lose its record of the remote system's host key.
  2. The remote system has been reinstalled. To check on this possibility, contact Joel Seber (CH301, x3734) or Mike Renfro (CH314, x3601). The likelihood of a complete system reinstall on a CAE system is pretty low, however.

If you've verified that neither your computer nor the CAE system has been reinstalled, STOP NOW and contact Mike Renfro or Joel Seber. There is a chance that a router or other system between your computer and the CAE lab has been broken into, and opens up the possibility that your password or other information could be intercepted.
Enter your CAE network password when prompted. If you typed it correctly, you should be logged into the remote system, and should see the remote system's $ prompt. Once you see the remote system's $ prompt, you can run most graphical applications by typing their command. For example, molden is run by typing molden and pressing the Enter key:

Linux graphical ssh session