Bits & Bytes online Edition




VNC remote desktops on MPCDF Linux systems

Klaus Reuter

While command-line based terminal sessions via SSH should certainly satisfy most requirements of users involved in scientific computing, it is sometimes desirable to have a graphical remote desktop session running on a remote Linux server. To serve that purpose, VNC (Virtual Network Computing) provides a graphical remote desktop system that uses the RFB protocol (Remote Frame Buffer) to control a graphical desktop session on another computer over a network. In particular, the performance of VNC is superior compared to traditional X forwarding, especially when dealing with complex graphical interfaces on wide-area networks.

At the MPCDF, a typical scenario would be to run a graphical tool (e.g. a debugger, a performance analysis tool, or other software such as IDL, Matlab or Python/ipython/matplotlib) interactively on a Linux cluster or on the hydra supercomputer in a VNC session. A particularly useful feature of a VNC session is its persistence. Users may disconnect from the VNC session and reconnect later, potentially from different computers at different locations. Programs that run within the session continue to run as long as the VNC session is not shut down or killed.

For plain text applications, the GNU 'screen' tool offers similar persistent functionality at a much smaller resource footprint. Please consider using 'screen' instead of VNC in case you don't need to run GUI applications.

Detailed documentation is provided on the MPCDF web page at Network --> VNC. VNC sessions can be launched on most interactive MPCDF Linux machines including the hydra login nodes.