From: Maria Dimitrova (
Date: Sun Jan 24 2021 - 03:20:17 CST

Dear John,

Thank you for the suggestions, I found the solution! It was indeed
caused by blocked GLX over ssh. I googled how to enable it and adding
these lines to xorg.conf helped:

Section "ServerFlags"
     Option "AllowIndirectGLX" "on"
     Option "IndirectGLX" "on"

Best regards,


On 23.1.2021 22.07, John Stone wrote:
> Hi,
> The likely issue with Ubuntu 20 is that they're using a newer variant
> of the X11 servers, and of late I have heard that some distributions have
> comletely disabled support for remote GLX protocol by default.
> GLX is the API layer that carries the OpenGL rendering commands
> (both local or remote), so that may explain why it stoppped working
> with the new Ubuntu installation. It might be that setting up a VNC
> server (or similar) is the best (albeit not simplest) resolution
> to your problem. Going forward I expect that man more people will
> run into these same problems as the pursuit of greater computer security
> causes more Linux distributions to disable and/or remove support for
> remote windowing system protocols like GLX by default.
> Best regards,
> John Stone
> On Fri, Jan 22, 2021 at 10:21:56AM +0200, Maria Dimitrova wrote:
>> Dear Ashar,
>> Thank you for the suggestion. We only have one login node. It is our lab's
>> minicluster. Axel suggested that it is likely due to different OS, which
>> is quite likely - I am running Ubuntu 20, while on the cluster we have
>> CentOS 7. CentOS does not feature the latest libraries and packages.
>> Kind regards,
>> Maria
>> On 21.1.2021 15.02, Ashar Malik wrote:
>> Dear Maria,
>> X forwarding works with other programs and I also see VMD's main
>> window, just that the OpenGL does not function properly
>> Are you connecting to the same node that other computers connect to and
>> use VMD in gui?
>> If you are able to see vmd main window (start on cluster) and displayed
>> on your end when using ssh with graphical support then a likely
>> explanation for VMD not fully starting (i.e. just the graphics window
>> [OpenGL] failing) on the server can be that the node you are connected
>> to does not support it?
>> Unfortunately, this is all I can suggest. Perhaps someone else can add
>> to this.
>> Regards,
>> /Ashar