Desktop#

The Desktop app will launch a light-weight (Xfce) desktop environment in an interactive job. Its main purpose is to run graphical software for which there isn’t (yet) a dedicated app available.

VSC clusters that support the Desktop app:

KU Leuven
VUB

Tip

Once the Desktop app is active, you can grant view-only access to other VSC users. In the ‘My Interactive Sessions’ menu, right-click the ‘View Only (Share-able Link)’ button to copy the link and share it with others. Any VSC user with the link can view your Desktop session in real-time, which is especially helpful for job troubleshooting and hands-on training.

Tip

In Chromium-based browsers such as Google Chrome and Microsoft Edge, the clipboard in the Desktop app will have the same content as your device, meaning that you can copy-paste text to and from the Desktop as expected. Other browsers, like Firefox and Safari, do not currently support this and in that case you will need to transfer text through the clipboard in the panel on the left hand side.

Using applications in the Desktop#

For improved graphics performance, we recommend the following workflow:

  1. Select the interactive partition on the wICE cluster and request one GPU instance.

  2. In the desktop environment, open a terminal window and load the module of your graphical software.

  3. Launch the executable with vglrun to enable hardware acceleration:

    vglrun <executable>

  1. Select the Anansi cluster and request some fraction of a GPU.

  2. In the desktop environment, open a terminal window and load the module of your graphical software.

  3. Launch the executable with vglrun to enable hardware acceleration:

    vglrun <executable>

Additional site-specific constraints are listed below.

Mainly due to security concerns, the KU Leuven OOD Desktop app is run within a minimalistic container. As a result some functionality is deliberately missing:

  • Slurm-related commands such as squeue, sbatch, srun, … and sam-balance, sam-statement, … are unavailable.

  • No browser is provided within the Desktop app (see alternatives below).

Some applications are currently unavailable but may be enabled in the future (such as myquota, apptainer and archive managers such as xarchiver).


Using your local browser where needed

Certain applications expect that you have a browser at your disposal.

The more common case is where the application starts a server to which you are expected to connect with a browser (examples: JupyterLab, Streamlit, CryoSparc). To use your local browser for this purpose, you only need to set up a suitable SSH tunnel with for example OpenSSH or PuTTY.

Some applications may produce static HTML files instead (example: LinaroForge). Other than simply transferring these files to your local device, you can also view these by starting a local HTTP server and applying the SSH tunnel approach described in the previous paragraph. An easy way to start such a server is the Python http module (added in Python 3.5):

/usr/bin/python3 -m http.server -b localhost <port>

Applications menu

The Applications menu on the top left will offer a number of shortcuts. Note that some may be missing in case you have changed the value of the XDG_DATA_HOME environment variable in your ~/.bashrc to something other than $VSC_HOME/.local/share.

(N/A)

Tips for NoMachine users#

KU Leuven

If you have been using the NoMachine desktop, you may need to do a few things differently when switching to the OnDemand Desktop:

  • For browser-related applications, see the section above. Note that in certain cases this means the Interactive Shell app may suffice and you may not need the Desktop app.

  • If your graphical application is available as a dedicated Interactive App we recommend using that instead of the Desktop app (examples: MATLAB, ParaView, Fluent).

  • The standard text editor is Mousepad (not Gedit).

  • As an image viewer you may use the display command provided by the ImageMagick modules, but we would rather recommend the viewer that is integrated in the File Explorer.