Computational Cluster Programs

NX Client

NX is a secure, compressed protocol for remote X Window System connections. You can use nx if you need to run graphical applications on Hoffman2 Cluster from a local Windows machine. There are free NX clients available from NoMachine (www.nomachine.com) for Windows, Linux, Mac OSX, and Solaris. This page describes detailed procedures for Windows. Procedures for other NX clients are similar.

How to Download NX Client for Windows

  1. Point your browser at http://www.nomachine.com
  2. Click the Download tab ( http://www.nomachine.com/download.php)
  3. In the NX Client Products section, click the download arrow to the right of NX Client for Windows (http://www.nomachine.com/download.php/Prod_Id=3205)
  4. On the download screen, click the Download package button.
  5. Click the Save File button. This will download nxclient-3.5.0-7.exe (current version as of July 2011) to your local machine and save it, probably in your My Documents\Downloads folder.

Install

  1. Click the nxclient-3.5.0-7.exe file that was downloaded.
  2. Click the Run button.

The NX Client for Windows Setup Wizard will start. The rest of this page presumes you have accepted all the setup defaults. Detailed information on NX Client for Window configuration is available at http://www.nomachine.com/documents/configuration/client-guide.php

Configure

Configuration requires a copy of the Hoffman2 NX client key file. You may want to obtain a copy of this file before proceeding.

  1. Click the NX Client for Windows icon on your desktop.
  2. In the NX window, it will ask for three pieces of information:
    3. Login: your-Hoffman2-Cluster-login_id
    Password: your-Hoffman2-Cluster-login-password
    Session: Hoffman2
  3. Click the Configure... button.
  4. In the General tab Server section enter or verify the following information.
    5. Host: hoffman2.idre.ucla.edu
    Port: 22
  5. In the General tab Server section click the Key... button.

    6. Delete the contents of the window that appears (the DSA key). Either paste into it the contents of the file /etc/nxserver/client.id_dsa.key from the Hoffman2 Cluster, or click the Import button to select a local file that contains a copy of that key.

  6. Click the Save button on the Key management window.
  7. In the Desktop section select or verify the following information. Compression level depends on type of internet connection that you select.
    8. Select type of your internet connection. ADSL (default)
    Unix
    GNOME
  8. Click the Save button on the General tab window.

How to get a copy of the Hoffman2 NX client key

NEW KEY December 1, 2011. There is a new key for the new nxserver that was installed along with CentOS 6. If your NX client is configured with the old key, you will need to reconfigure it in order to connect to Hoffman2.

Use an scp or sftp client program on your local machine to download this file. For example:

scp login_id@hoffman2.idre.ucla.edu:/etc/nxserver/client.id_dsa.key  .

The above command will save a copy of client.id_dsa.key in your current directory.

Or, use an ssh local client to login to Hoffman2 and display the key file, and copy-and-paste it to a text file on your Windows machine (e.g., a Notepad file).

If you don't have another local ssh client on your desktop, you can use nxssh. To connect to Hoffman2 Cluster with nxssh, do the following.

Start -> Programs -> Accessories -> Command Prompt

In the Command Prompt window, enter:

cd C:\Program Files\NX Client for Windows\bin
nxssh -l login_id  hoffman2.idre.ucla.edu

At the Hoffman2 shell prompt, enter:

cat /etc/nxserver/client.id_dsa.key

Copy and paste the key text into a text file. For example, open Notepad and paste the entire text of the key file including the lines:

-----BEGIN DSA PRIVATE KEY-----
 
-----END DSA PRIVATE KEY-----

The default TestDrive key that comes with NX is located in
C:\Program Files\NX Client for Windows\share\keys\server.id_dsa.key

Run

Start the NX Client for Windows from the Start menu:

Start -> Programs -> NX Client for Windows -> NX Client for Windows

or, click NX Client for Windows desktop icon. (C:\Program Files\NX Client for Windows\bin\NXWin.exe)

Enter your Hoffman2 Cluster login id and password in the pop-up window.

Click the Login button.

The First Time you Connect

  • The first time you connect to the Hoffman2 Cluster, the NX Client for Windows will ask you to verify that the Hoffman2 Cluster fingerprint is correct. You can check it against:
    • http://www.ats.ucla.edu/clusters/hoffman2/head_node_access
  • The first time you connect to Hoffman2 Cluster, Windows may open up two security alert windows: one for nxssh and one for nxclient. You should click the Unblock button in each alert window. For example:
    • Windows Security Alert

    To help protect your computer, Windows Firewall has blocked some feature of this program. Do you want to keep blocking this program?

    Name: nxclient

    [Keep blocking] [Unblock] [Ask me later]

How to get a terminal window and shell prompt

After you have logged in to Hoffman2 and the gnome desktop is displayed, select:

Applications -> Accessories -> Terminal

How to logout

From the gnome desktop, select:

System -> Log Out login_id ...

A small window will open. Click the Log Out button.

Logging out will close the NX Client for Windows program.

 

December 2011