virtualbox.org

I'm using VirtualBox with a Windows 8.1 host and Arch Linux guest. Since I upgraded to 5.0, my guest won't start with dual monitors, and only recognizes that one monitor is plugged in. I've configured the VirtualBox display settings to show two monitors, so I don't know what I'm missing.

Have the Arch Linux guest additions been updated to work with VB 5.0?

I am having the same issue and I am running on the same host. The Archlinux guest additions (virtualbox-guest-modules) have been updated to version 5.0.0-1.

Since Arch Linux is not a supported guest I guess it's time to ask over at the Arch Linux forum.

Ok, will do. Thanks.

Edit:-

While the bug does not reference version 5 of virtual box, I believe task 45748 on the archlinux bug tracker is relevant (excuse the lack of a link, but my account is not old enough to post links).

Having the same issue here, could it be a bug coming from the new version of VB?
EDIT/SOLUTION: Rolling back virtualbox-guest-* packages to 4.3.28 fixes the issue of the second screen not appearing in xrandr at all.
Now the second monitor appears as "disconnected" in xrandr, before the downgrade it did not appear at all.
Still not ideal though, anyone know how to fix that?

Anyone find a solution yet? Same issue here after upgrading.

mears11 wrote:Anyone find a solution yet? Same issue here after upgrading.

I am on 5.0.8
vboxguest is also 5.0.8

i have two monitors configured, as shown in the pictures submitted by other posters
on my laptop i have two virtualbox windows, one for each configured monitor
when i run the virtual machine on my desktop, i only have one virtualbox window

running xrandr i get VGA-0 connected primary
VGA-1 disconnected

There might be a bug in virtualbox that only surfaces with certain kinds of hardware.

the host OS is windows 10 both on the working laptop and the nonworking desktop.

Any idea what logfiles to look at to see what went wrong when virtuabox tried to create the second window?

i have the bug on two deskttop systems, both of them running AMD graphics adaptors

all 3 systems show
00:02.0 VGA compatible controller: InnoTek Systemberatung GmbH VirtualBox Graphics Adapter
when running lspci

the ciient os is ubuntu 14 something

I have the same setup and symptoms as @pinball. Anyone have any ideas?

Same happened to me after I upgraded my guest extensions to 5.0.8 on Mageia 5, on Windows host (tested host Virtualbox versions 4.x and 5.0.10).

I used the attached workaround/hack in vboxvideo driver to force 2 monitors and it seems to have worked. I upgraded vboxvideo to 5.0.10 at the same time, so not 100% sure if it was the upgrade or the hack that made it work.

AnssiH wrote:Same happened to me after I upgraded my guest extensions to 5.0.8 on Mageia 5, on Windows host (tested host Virtualbox versions 4.x and 5.0.10).

I used the attached workaround/hack in vboxvideo driver to force 2 monitors and it seems to have worked. I upgraded vboxvideo to 5.0.10 at the same time, so not 100% sure if it was the upgrade or the hack that made it work.

AnssiH - I'm at 5.0.10 so and had the same problem. I am going to try your "patch" - do I paste the file into a specific directory or copy the contents into a specific file?

I had this problem on all the 5.0 versions I tried including the last one 5.0.12 before I somehow solved it.

What was happening for me was after the session had started up my first Virtual Screen was set to the proper Host Screen but my second and third had no selection. Under xrandr it showed on VGA-0 connected the rest were disconnected.

I tried selecting the proper Host Screen under the Virtual Screen 2 and 3 and restarting my session. But it always came back up unselected and xrandr showed disconnected.

Somehow I got my second to show up and I have not a clue how. I was trying different Xorg configuration files, etc.

But I know the last thing I did to get the third screen to show up. Instead of waiting for the X session to fully start and then setting the Host Screen, I set the host screen as the session was starting. That seemed to do the trick. X then probed and recognized my third monitor. I'm guessing that maybe it has to do with VirtualBox not assigning a default host screen to the second and third virtual screens and the selections done after the X session starting not being saved. So by selecting them during startup and X then recognizing them they now "stick".

All the Xorg and othe changes I did I have reversed out and my virtual screens are all still working.