Mismatched Multi-Monitor Configuration Between Linux Host and Windows 7 Guest

[Scapulomancy]

I run a Xubuntu 18.04 host with a Windows 7 guest. My setup includes three monitors:

* A 1080p monitor running on HDMI (my primary monitor)
* A 1680x1050 monitor running on VGA
* My laptop display

In Xubuntu, my monitor arrangement is fine. However, if I start up my Guest with more than one monitor, there's a mismatch on the second and third monitors. Essentially, the Windows seems to think that the second monitor (the 1680x1050) has the laptop display resolution and the third monitor (my laptop display) has the 1680x1050 resolution.

Let me illustrate in pictures. Here's the display configuration of my host: https://i.imgur.com/8Iqgkpz.jpg
And here's the display configuration on my guest: https://i.imgur.com/kEWaQAh.jpg

Now, with the guest in full-screen mode, here are what my three monitors look like:
Monitor 1: https://i.imgur.com/c528HJJ.jpg
Monitor 2: https://i.imgur.com/W4obQKB.jpg
Monitor 3: https://i.imgur.com/1b3EepG.jpg

As you can see, monitors 2 and 3 appear to have flipped resolutions. No amount of playing around with the monitor configurations in the display panel in either my host or my guest appear to be doing much good.

I'd appreciate any advice the community can provide on solving this problem.

[mpack]

"Mismatch" implies that something called a "match" exists. It doesn't. If VirtualBox simulates three virtual displays there is no necessary or intended correlation between those and any physical displays you have. It's presumably up to you to drag the VM windows onto whichever physical monitor you like. Even have all three windows on one monitor perhaps.

Think about it. What would be a "matching" mapping if you allocated four virtual displays to the VM?

Btw, that is a general principle of VMs: simulated hardware has no necessary correlation with any actual host hardware, though some kind of mapping from one realm to the other - as defined by you - is often possible.

[Scapulomancy]

I understand what you're saying, but I'd still like to know how to make the three VirtualBox screens match the resolutions of my three monitors (if such a way even exists) when I go into fullscreen mode. No amount of playing around with the Display in either host or guest seems to be doing much good.

[socratis]

You can assign each virtual monitor to a physical monitor. Either from the mini-toolbar, or by pressing HostKey+Home and you get the VirtualBox menu. You then go to the menu: View » Virtual Screen # » Use Host Screen #. Play with them, you're going to get it...

Another way is to leave FullScreen mode and get into Windowed mode, the normal/default. Arrange the windows (virtual screens) to your preferred Host screen, and then go to FullScreen mode. Each window should go into FullScreen on its own screen.

[Scapulomancy]

Okay, when I play around with the View -> Virtual Screen # -> Use Host Screen number in fullscreen mode, it's not making a difference for monitors 2 and 3. Let's say I have virtual screen 2 running on monitor 2 (1680 x 1050) and virtual screen 3 running on monitor 3 (1366 x 768). In this arrangement, virtual screen 2 is showing the resolution of monitor 3, and vice versa. Now let's say I go and change virtual screen 2 to use host screen 3. Now virtual screens 2 and 3 switch places, but so do their resolutions. Virtual screen 2 moves to monitor 3 AND changes its resolution to 1680 x 1050, so the problem stays. This seems like very strange behavior to me.

Virtual screen 1 is still on monitor 1 and still displaying a resolution that matches the monitor.

The windowed mode trick works appropriately. It's not ideal, but each virtual screen at least matches the resolution of its respective monitor at that point.

I'd appreciate any other suggestions the community may have.

[ChipMcK]

a google search Mismatched Multi-Monitor Configuration Linux

[Scapulomancy]

Yeah, but none of those results appear to have anything to do with VirtualBox. My Linux host is running my multi-monitor setup without a problem.

[ChipMcK]

your monitors are run by Linux host, just as macOS does when it is the host.

[Scapulomancy]

I know. But I used to have a setup that was the other way around: a Linux guest running on a Windows host. In that setup, both the host AND the guest scaled to each monitor correctly, even when the guest was in fullscreen mode across all three monitors. I don't understand why the same isn't true for the Linux host/Windows guest configuration.