VirtualGL shows ERROR: Could not open display :0

we’re using Alma Linux 8.5 and have built an NVidia graphics card into our servers and installed the appropriate drivers. In order to be able to use the graphics performance remotely with TigerVNC, we have installed and configured VirtualGL. However, when starting our OpenGL applications, the following error always occurs:
[VGL] ERROR: Could not open display :0

Maybe you have a solution for me to fix this error.
Thanks in advance.

@fiberkill ,
admittedly, I only have a theory here, but do you have X11 (GDM/GUI desktop/etc…) or Wayland installed?

That’s what the error implies to me.

Hi, i found the problem.
I forgot to start and enable lightdm.service.

now it’s working.


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HA! Good for you @fiberkill. Change the title of your initial post to have “SOLVED:” to indicate you got the problem solved, to help others too.