If you need to run a computing job that will take a while, please use one of these techniques to avoid having to tie up a computer's console for the whole time:
The command will continue to run after you log out. All output will go to a file called nohup.out. You can choose your own output file with:
nohup command > output-file 2>&1 &
If you do this on any machine in room 103 or 218 use the nice
command at the beginning to keep from bogging down the machine:
nohup nice command.....
You do not have to do this with "back room" machines like the MathVaders.
This is a powerful utility that lets you create a terminal session, start whatever you want and then "detach" it and log out. When you log back in you can re-attach, see what your program has been doing in your absence, and tell it what to do next.
Log in to the machine of your choice and think of a name
for your session. Then enter:
screen -S Session-name
where Session-name is the name you chose for your
session.
After you have gotten your program going, you can detach from the session by holding down the Ctrl key and pressing a followed by d. You can now log out.
When you log back in, reconnect to the session by typing:
screen -r Session-name
If you do not remember the session name, you can see a list of
sessions with:
screen -ls
Or, if you have only one detached session, you can reconnect to it
with:
screen -R
Screen has many other useful features - see the manual page for more information.
At the command line, type nxclient. You will get a login window with blanks for username, password, and session. Under session, choose the computer you want to run on. Then enter your username and password and click Login. If this is your first session on that computer, you will be told that the machine's authenticity cannot be established and asks if you want to continue; click Yes. After a little while (20-60 seconds, depending on system load) a window will open containing a complete X-windows desktop on the remote computer. If you get an error, click the Details button and email the results to the systems staff.
By default, the desktop is 1024 pixels wide by 768 high. You can change this by selecting the Configure button.
After you have started your computations, hold down the Ctrl and Alt keys and press the T key. You will be presented with a dialog box with three choices: suspend, terminate, or cancel. To disconnect while leaving your program to run, click suspend. The window will close.
To reconnect to a disconnected session, do the same thing you did to make the connection originally. Instead of starting a new session, you will be reconnected to the old one. If it shows you a box saying that you have a disconnected sesssion, but does not allow you to resume it, you are using a computer that is not compatible with the one that created the session. Try connecting from another machine or ask the systems staff for assistance.
Normally, when you are completely done, you can end your session by selecting Log Out within the NX window. If this does not work for some reason, you can use Ctrl-Alt-T and then terminate to end the session.
We may be able to install the NX client software on your laptop. Contact the systems staff for more information.