NoMachine - Basic Usage

Basic usage of NoMachine and the Gnome dekstop.

This page cover basic usage of no-machine to connect to a new desktop, terminate a session, disconnect from a session (leaving it running unatended) and resuming a disconnected desktop session. There is also an introduction to the Gnome desktop environment. This assumes you have allready installed Nomachine enterprise client on the device you will be using to connect to SPECTRE. If you have not, please refer to the NoMachine 5 page.

Starting A New Desktop Session

  • Launch NoMachine on your desktop/tablet.
  • If the SPECTRE or ALICE connection is all-ready present, double click on this to connect. If not, follow the instructions on the NoMachine page to install the ALICE session file and/or the SPECTRE session file..
  • Enter your university username and password when prompted. Note your username should not contain the uol/ domain text and is case sensitive. Do not select the "Save this password in the configuration file" box, passwords saved in this way will be saved in plain text (unencrypted) and are therefore highly vulnerable. For example for user cjm14:Logging in to spectre. Note the username does not have a uol/ at the start and is case sensitive
  • You will now be presented with the sessions page. This lists active desktop sessions on SPECTRE or ALICE along with giving you the option to start a new session. In this case we wish to start a new Desktop session, so click on the "new session" button:SpectreSessionList
  • You will now be presented with a new desktop session:SpectreGnomeDesktop
  • You should now be able to interact with the desktop, opening and using programs as you would on your desktop machine.

Basic NoMachine features

Changing desktop resolution, making NX fullscreen, returning to windowed mode.

First, connect to SPECTRE or ALICE as above.

The NoMachine menu and settings.

The NoMachine menu system is unusual. To open the menu, you need to move your mouse to the extreme top right of the NoMachine window, this will cause the corner to "Peel" as shown below, click this region:


Alternatively, the key combination "ctrl-alt-0" (number zero, not the letter o), will also start the menu.

The row of icons along the bottom of the menu (shown below) are, from left to right:

  • Scale remote desktop: When this is selected, the remote desktop will run at it's own resolution, independent of the size of the window on your local machine. This is mutually exclusive with the next option.
  • Resize remote desktop: When selected (the default), the remote desktop will be resized to match the local window size it will be resized every time you resize your local window.
  • Full-screen: Make your NoMachine window full-screen and hide the window decorations (if you have multiple monitors, the window will be full-screened on the current monitor.
  • Fullscreen on all monitors: Make the NoMachine window fullscreen, spanning all monitors you have attached. This will not be selected unless you have multiple monitors configured.
  • Minimize window: Minimizes the NoMachine window.
  • Display settings: Advanced display settings. This is covered in the Advanced NX Features Guide.


The large icons in the centre of the screen will be covered in the Advanced NoMachine Features Guide.

Terminating Your Desktop Session

Terminating the desktop session will log out of your remote desktop, killing any programs that you are running there (note: this will NOT kill PBS batch processes you may have started from the session, only interactive processes).

The simplest method is to select "Logout" from the gnome System menu:


Alternatively, you can simply close the no-machine window and select "Terminate Session" when prompted.

Disconnecting from a desktop session

Instead of terminating the desktop session on exit, you can disconnect and leave it running. This allows programs running in that session to continue. You can then reconnect to the session from the same or any other client computer. There are a few points to note about disconnected sessions:

  • Disconnected sessions are still using resources on the server. If you do not have a good reason to leave the session running, log out instead!
  • To conserve server resources, sessions which are disconnected for more than 7 days will be automatically terminated.
  • There is a 2 hour hard CPU time limit on running processes, this means you will not be able to keep cpu intensive tasks running in a session (disconnected or live) indefinitely. If you need to run software which must do lots of processing, make use of the queuing facilities to run this on one or more compute nodes. If you need high performance, interactive access to long running, cpu intensive processes, please contact and we will help you to set this up.

To disconnect from a running session, either close the NoMachine window or click on the power icon at the bottom right of the NoMachine menu. Select "Disconnect" from the dialogue box when prompted.

Reconnecting to an existing desktop session

Once you have disconnected from a desktop session (as in the previous section), you can then reconnect.

Start NoMachine and log in to ALICE as usual, at the sessions screen you should see your existing session, as below (in this case the user cjm14 has an existing session):


If there are many sessions listed in the window, including those of other users, either type your username into the search bar, or change the "All Desktops" settings to the right of the search bar to "My Desktops".

Double click on the session icon to reconnect to that session. If the session is all-ready connected from another client, the original client will be disconnected and the session reconnected on the new client.

Using the gnome desktop environment

The gnome desktop environment should look familiar to users of most desktop operating systems. For more advanced features, please search on the internet or if you have specific questions, email Be aware if using online documentation, the current version of Gnome (version 3) is very different to the version on ALICE and SPECTRE (version 2).

Menu Panel

Along the top of the desktop is the menu panel:

Basic usage of NoMachine and the Gnome dekstop.GnomeMenuPanel

This contains (form left to right):

  • The application launch menu: Contains a menu of applications that can be launched on the desktop. This is a limeted selection. Most applications are instead accessed via the command line.
  • The places menu: Contains locations which can be opened in the file browser.
  • The system menu: Contains the desktop settings, Scientific Linux documentation and logout submenus.
  • Quick launcher icons: Clicking on these launches a program - programs can be pinned here from their entry in the applications menu.
  • The system tray: Contains the NoMachine icon and clock.

Most applications are not intended to be launched from the desktop environment, instead they can be launched from the command line after opening a terminal. The terminal can be started from the first quick launch icon, under Applications > System Tools > Terminal or by double clicking on the terminal icon on the desktop. A great deal of information on using the Linux command line is available on the internet (search for "linux command line tutorial" in your favourite search engine). IT Services also run courses to help you get started using the Linux and the Leicester high performance computing systems.

Task Bar

The task bar is located along the bottom of the desktop. It contains a list of running programs, allowing you to switch between windows with a single mouse click. To the right of the bar is the pager. A feature of many Unix desktops is that they permit multiple workspaces per session. Each workspace can contain different windows and you can switch between them using the pager. By default 2 workspaces are available when you login. If you need more, right click on the pager and select "preferences". This will allow you to add or workspaces.

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