How do I create a virtual secondary screen in X11?

Question

I'm trying to use xvfb as a secondary screen, but I am struggling getting the two screens working together. xvfb does not seem to have the randr extension.

So is there another possibility to create a virtual screen that could be in dual-head mode together with my real screen?

score 3 · Answer 1 · answered May 03 '11 at 12:06

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Xnest does not support randr either. But Xephyr does.

answered May 03 '11 at 12:06

ceving

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How exactly do you think `Xephyr` can "extend" Display `:0` with another "graphics device", that OP can position with `xrandr` **relative** to his existing screen? Could you elaborate? – Alex Stragies Dec 11 '16 at 00:44
@AlexStragies See here: https://en.wikibooks.org/wiki/Multiseat_Configuration/Xephyr – ceving Dec 12 '16 at 09:04
Xephyr is nice tech, true, but: The OP is **not** asking for a multi-seat configuration! → Not an answer (to this question). – Alex Stragies Dec 14 '16 at 18:58

score 1 · Answer 2 · answered Apr 29 '11 at 23:45

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You could try using the xf86-video-dummy driver with Xorg to make the second screen.

answered Apr 29 '11 at 23:45

alanc

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This sounds like a viable idea. Have you tried it? If so, could you elaborate? I'm also following the subject of (hot-)adding virtual graphics devices (with virtual screens). And some details would really make this a better answer. – Alex Stragies Dec 14 '16 at 19:02

score 0 · Answer 3 · answered Apr 28 '11 at 20:37

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Have you considered using Xnest? That works by creating a virtual X server that just proxies all of its incoming X protocol calls to the real X server. It also does not support randr, however, so you may want to consider removing your dependency on that (by switching to an alternate window manager or the like).

answered Apr 28 '11 at 20:37

fluffy

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That looks good!I will look into using Xnest together with xinerama to archieve my goal. Stupid me: I thought Xnest only was for testing purposes in terms of creating a kind of jail for Xclients. Anyway, thank you very much! – Apr 28 '11 at 20:54
How exactly do you think `Xnest` can "extend" Display `:0` with another "graphics device", that OP can position with `xrandr` **relative** to his existing screen? Could you please elaborate? – Alex Stragies Dec 11 '16 at 00:53
If you had asked me 5 years ago when this question was still fresh in my mind and I was using Xnest regularly, I might be able to answer... – fluffy Dec 11 '16 at 01:34

How do I create a virtual secondary screen in X11?

3 Answers3