Bdtyktl

I have been fighting with multiple (2+, not 1+) monitors with my laptop on ubuntu for a while. Same old story with driver support issues, etc. The solution I have currently is one traditional extension monitor and another running from a USB converter, which isn't ideal. My question is ... is there a way I can run a host (in this case my ubuntu laptop) and connect to it via VNC and using the VNC connection add as many monitors as I have access to on the "windows" VNC client? The problem I see with this from what I have read is that the host needs to know about all the monitors prior to the VNC connection... not after.

I figured this might be a creative way for me to finally have 2-3 (or more) monitors connected to ubuntu laptop without all fighting with drivers and poor performance when attaching displays to USB adapters.

I'm not worried about speed with VNC, it would all be local network traffic.

A bit of research
https://support.realvnc.com/knowledgebase/article/View/379/6/how-do-i-map-multiple-vnc-viewer-monitors-to-multiple-vnc-server-monitors

https://support.realvnc.com/Knowledgebase/Article/View/341/12/can-i-view-only-one-of-the-displays-of-my-multiple-monitor-computer?

If a USB video adapter is "less than ideal" for performance reasons, unless it's strictly a USB bus bottleneck that's the problem, there probably are no other ways to add the same number of monitors with acceptable performance, at least not if there's a lot of motion. That said, here's one way to essentially have as many monitors "attached" to that laptop as you want, all under the control of a single keyboard & mouse, without requiring specialized hardware:

Set up VNC on the laptop so that when you log in it's connecting to its own separate X server (vs. the :0 display that's currently driving your monitors). Now you can set up addition computers. From each of them, you can open a VNC session (with its own independent X desktop session) and run it full-screen. (You could also directly use X via LTSP or otherwise or any other remote control method to connect to the X sessions; just get them on the screen. With VNC, your other computers don't even have to be running Linux.) Okay, great. Now you have 25 displays next to each other, but you also 25 kbd/mice pairs. Now what?

First, install VNC on each of the other computers. Verify that you can connect to each of them and see the desktop they're displaying. So from the laptop you can VNC to another machine, and see the "private" desktop that's being generated on your own laptop, but displayed on the other machine's monitor and also in your own VNC client window. Okay, now we know that's working. It's still not what you want, so here comes the next step.

Enter "x2vnc". Basically it's a VNC client that sends kbd/mouse events, but doesn't bother to get video back. Instead of a traditional client window (which you activate so that it knows to send the mouse/kbd events to the remote machine instead of your local session) you configure it so that it's activated when you move the mouse to the edges of your screen. You could have it connect either to the machines that are displaying your extra desktops or to the vnc servers running on your own laptop that they're connected to.

In any case, the x2vnc magic makes it so that you can have a monitor attached to a remote computer sitting to the right of your main one, and when you move your mouse past the right edge of your screen, it magically keeps going from the left of the righthand monitor as if it were a dual display, when in reality you're controling the other computer (which in this case is in turn controlling a desktop session on your own machine). It keeps track of where the mouse is so that when you come back left your pointer reappears on your local display at the right time and place so the whole thing feels very natural.

It's been a while since I've played w/ x2vnc. I know it's flexible, but I don't know how. In this way, though, you could have at least 4 other machines you're connecting to: top, bottom, left, right edges of the screen. And, of course, if one of your other machines has 2 monitors and lets you span the VNC viewer across the two of them, then that lets you go further away from your local central display. For that matter, you could probably run x2VNC (win2VNC on Windows machines) on one remote machine so that it would then control another as you kept moving the same direction; this would allow you to have a long chain of monitors in one direction, each one adding another layer to the a-controls-b-which-controls-c-which-controls-d-which-views-a2 chain. Hundreds of monitors!

Of course, with multiple independent X servers running, you're still not going to be able to smoothly transfer windows across sessions (though I almost seem to remember an app that would kinda let you do that, acting as a broker between apps and multiple X servers). If you instead configured the other machines as "fat clients" (using LTSP) you could it so that you're at least semi-synchronized app-wise to your notebook (You have to periodically update your fat client image to keep it in sync with what you have installed) while utilizing the CPU/Mem on the other machines to lighten your load that way on the laptop.

Seems like an awful lot of infrastructure for a laptop, though!