X2Go (External Link) allows you to interact with ALICE or SHARK through a graphical desktop instead of the command line interface. For some applications, using X2Go can be more efficient than running X11 forwarding. X2Go is available for Windows, MacOS and various Linux flavors.
This page shows how to setup and make use of X2Go on ALICE and SHARK
Getting X2Go
The X2Go client can be downloaded from the X2Go homepage (External Link) and installation instructions are available here (External Link).
For Linux, x2go is available through the standard package manager of several distributions, e.g.,
CentOS/Fedora/Red Hat: yum install x2goclient
Ubuntu/Debian: apt-get install x2goclient
Arch Linux: pacman -S x2goclient
For Windows, you can choose between a Windows installer or a portable version
For MacOS, you can choose between installer for different versions of MacOS
You do not need the X2Go server.
Setting up the connection
If you have installed the X2Go client, you can set it up for ALICE or SHARK:
ALICE | SHARK | |
|---|---|---|
 | Start X2Go, select “Session” in the menu and then “New Session”. | Start X2Go, select “Session” in the menu and then “New Session”. |
 | In Session name you can replace “New session” by a more suitable name, e.g., “ALICE 2”. In the Server settings,
You can also set the path to your ssh key in Use RSA/DSA key for ssh connection if you do not want to authenticate using your password. In Session type, select either Finally, confirm the settings by clicking OK. | In Session name you can replace “New session” by a more suitable name, e.g., “SHARK 1”. In the Server settings,
You can also set the path to your ssh key in Use RSA/DSA key for ssh connection if you do not want to authenticate using your password. In Session type, select either Finally, confirm the settings by clicking OK. |
Using X2Go
If you have successfully completed the previous step, the X2Go main window will display a tile with the name of the session, the host (without the proxy server), the desktop environment, the desktop resolution of your X2Go session and sound enabled/disabled.
By clicking on the desktop resolution, you get a drop-down menu from which you select alternative resolutions.
By clicking on the tile, X2Go will initiate the process to connect to ALICE or SHARK. If you have not set your session to use ssh keys, X2Go will ask for ALICE or SHARK user password.
After you successfully authenticated, it usually takes a few seconds for X2Go to start your desktop environment on ALICE or SHARK.
When you are finished using your X2Go session, please log out of your desktop environment and do not just close the window in order to properly terminate your session. Otherwise, your session will be suspended and consume resources. We regularly check suspended X2Go sessions and terminate them if necessary.
Editing your existing X2Go session
The three horizontal lines in the bottom right corner of the session tile, allow you amongst other things to access the session preferences.
Available desktop and how to log out of your X2Go session
The following desktop environment are available:
on ALICE: XFCE, MATE
on SHARK: XFCE, ICEWM
The screenshots below give an impression of how the different desktop environments look like. The actual appearance of the desktop can vary between SHARK and ALICE and from user to user.
ICEWM
ICEWM is only available on SHARK
The ICEWM desktop for a new session
In order to log out, click on bottom-right icon, select “Logout” and then “Logout”.
Confirm that you want to log out, by clicking “OK” on the appearing overlay window:
MATE
MATE is only available on ALICE
The MATE desktop for a new session
In order to log out, click on “System” in the menu bar and then select “Log Out <user-name>”, where <user-name> is your ALICE user name.
Confirm that you want to log out, by clicking on “Log Out” on the appearing overlay window:
If you are seeing graphical issues when using MATE, try to disable the compositing window manager. You can find it under “System > Preferences > Windows” and then in the “Window Preferences”, disable “Enable software compositing window manager” under “General > Compositing Manager”
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XFCE
The XFCE desktop for a new session
In order to log out, click on Application in the top-left menu and select “Log out”.
An overlay window will appear, asking you to confirm by clicking once more on “Log Out”.
Mounting a local folder to the X2Go session
To easily access files from your local machine in your X2Go session, you can share local directories.
This can be configured during the first set-up of the session, or by editing an existing X2Go session.
Do note that accessing the files will happen over the network (they are not actually on ALICE or SHARK) and the share will of course close when you log off from X2Go. So this feature is most useful for quick lookups or for easily copying the files to your home directory.
In the Shared Folders tab of the Session preferences:
click on the folder icon next to the add button,
navigate to the directory on your local machine that you wish to share and click select folder,
then click on the add button,
make sure the checkbox for Automount is ticked,
using the steps above you can add multiple local folders,
finally, confirm the settings by clicking on OK.
When the session has started, you can access the file manager (or the terminal) to find you local folders under: /home/[USERNAME]/media/disk/
The names of the top directories may look a bit strange (e.g. starting with "_cygdrive"), but the file and foldernames within should look correct.
Best Practices
Always logout of your desktop environment in order to properly terminate your session. Do not just close the window because this will keep your session suspended consuming resources on the login nodes.
While there is most likely always a limited amount of time lag involved when using X2Go, you can try to improve the performance by changing the Compression Method in Sesssion preferences -> Connection.
Known Issues
There is a known issue that results in breaking the copy-and-paste functionality from the host to the server or the other way around. In some cases, it helps to enable do not use primary cliboard in Options -> Settings -> X.Org Server settings. Otherwise, it might be necessary to restart X2Go.