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Welcome to the NX page

This page is where CHG'ers go to learn about connecting to CHG machines through NX (nomachine). Since many users have reported problems connecting to the NX server, most CHGers have shifted to terminals on their desktops or to VNC sessions.

Intro to NX

NX Distributed Computing Architecture is a suite of technologies and commercial tools, designed to make network computing as easy and widespread as browsing the web. It consists of a thin layer of server software that enables any Unix computer to work as a terminal server. Clients are also available for a wide range of platforms and operating systems. NoMachine has chosen to build the foundations of its NX Distributed Computing Architecture on the well known and widely used X-Window System - the windowing system that's behind the Graphical User Interfaces of Linux and the Unix Operating System.

Installing NX

Configuring NX

Make sure to add the rain server key when configuring a new connection. The key can be obtained from Pete or Libby.

Troubleshooting NX

Error: NoMachine service not available on [server]

It may be that the your NX client key needs to be updated.

  1. Obtain the latest key from a sysadmin type.
  2. Replace the current key with the new key by either copying and pasting it or pointing NX to the new file containing the key.
    • The setting's location will vary depending your NX version and platform, but it is usually in the login settings panel.

General trouble connecting

Sometimes a recent update or unrelated connection failure on either end (server or client side) can cause your .Xauthority file to become corrupted. In this case, try renaming your .Xauthority file on both the server and client (it should be recreated automatically once you connect, at which point you can delete the old .Xauthority). In some extreme cases, try renaming your entire ~/.nx directory on both the server and client side (also should automatically recreate, though you may want to copy some of your settings from the old directory before deleting). On the server side, your .Xauthority and .nx directory should be located in your home folder. In Windows, they should be located in your user folder (not to be confused with your "Documents" folder).

xserver shuts down and user can't run xserver-related commands after being connected for 20 minutes.

Apparently in the new Mavericks OS, default ssh settings (as mentioned in ~/.ssh-config file) of ForwardX11Timeout parameter is 20 minutes, meaning that xserver is supposed to time out after 20 minutes in case of untrusted forwarding. ssh -X does untrusted forwarding of x server, so using ssh -X could trigger this problem.

Two possible solutions:
  1. Change ForwardX11Timeout parameter to something like 7 d (7 days). This will cause xserver to time out in 7 days instead of 20 minutes if you use ssh -X - however, this still leaves the problem of the session timing out.
  2. Use ssh -Y to connect (which does do trusted forwarding of xserver). It is not clear at this time if using ssh -Y means xserver will never shutdown.
~Information courtesy of Shrad

Log indicates authentication was successful, but cannot connect to NX session (linux box)

If the NX log indicates that authentication is successful but you still aren't able to connect to your NX session, you may need to kill all your processes (server side):

ps -u [username] #to list processes
kill -9 [pid] #list each process id (pid)