Yes, it is possible. You don't actually even need multiple X servers for multiple users to use VirtualGL at the same time. Multiple users can share the same GPU using VirtualGL. That is one of its purposes. In order to use VirtualGL with multiple GPUs, generally the easiest way to do it is to configure a single X server with multiple screens, so GPU 0 would be accessible by setting VGL_DISPLAY=:0.0 and GPU 1 would be accessible by setting VGL_DISPLAY=:0.1, etc. The reason why you are getting the pixel readback error is because, unless the X server is headless, it has to be attached to the physical display in order for pixel readback to work. The only way to use VirtualGL with multiple X servers (:0.0, :1.0, etc.) is if one or more of them is configured to be headless. (https://virtualgl.org/Documentation/HeadlessNV explains how to configure a headless X server with an nVidia GPU.)
On 10/9/17 5:35 AM, Jafaruddin Lie wrote: > Hi all > Simple question is if it is possible, on a single machine with multiple > GPUs, running different X servers on those GPUs, for multiple users to > use vglrun at the same time? > This is our current setup: > > 1 machine with 4 Nvidia K80 cards (latest drivers), running CentOS 7, > VirtualGL 2.5.2, TightVNC, and Mate Desktop. > > We have 2 xorg.conf (2 cards configured on each xorg.conf), and > currently we are testing whether we can bring up 2 desktop sessions via VNC. > The desktop loads, and we can see two different X servers running on > those 4 cards and the VNC servers running on different displays. > > The issue is with VirtualGL. The first user can do startx and run vglrun > glxgears, this will work fine. > When the second user startx, the first user's vglrun session will be > terminated with this error: > > [VGL] ERROR: OpenGL error 0x0502 > [VGL] ERROR: in readpixels--- > [VGL] 439: Could not read pixels > > The first user can run vglrun again once the second user stops their X > session. > My understanding is that with our setup, this should be do-able, right? > > Thanks. -- You received this message because you are subscribed to the Google Groups "VirtualGL User Discussion/Support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/virtualgl-users/e38fd010-f8e2-7faf-7e0b-2e3f68317985%40virtualgl.org. For more options, visit https://groups.google.com/d/optout.
