Arch Linux

scrouthtv

Member

Registered: 2019-10-15

Posts: 38

[SOLVED] VirtualBox dual monitors

I'm running an Arch Linux guest in a Windows 10 host using VirtualBox 6.1.2.

In the VBox config I set the monitors to two, but all monitors besides Virtual1 are disconnected in xrandr. So I first tried to manually install the guest additions with the iso as spydon tells in https://bbs.archlinux.org/viewtopic.php?id=200575 (iso and host version matching) but xrandr still only recognizes one display.

Then I uninstalled the iso package and installed virtualbox-guest-utils as well as virtualbox-guest-modules-arch as suggested here https://wiki.archlinux.org/index.php/Vi … _Additions. I enabled vboxservice.service but after a restart my xorg (lightdm) wont start at all:

lightdm.service: Start request repeated too quickly

Last edited by scrouthtv (2020-02-02 06:35:10)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,399

Re: [SOLVED] VirtualBox dual monitors

Check a potential xorg log, it's likely you are running into the early boot modprobe race, doing something like

echo drm > /etc/modules.load.d/drm.conf

from a root shell should help

scrouthtv

Member

Registered: 2019-10-15

Posts: 38

Re: [SOLVED] VirtualBox dual monitors

From the /var/log/Xorg.0.log:
Failed to load module "fbdev" (module does not exist, 0)
Failed to load module "vesa" (module does not exist, 0)
Falling back to old probe method for modesetting
...
Failed to initialize direct rendering DRI3.
...
Fatal server error:
failed to create screen resources(EE)

With the drm module as you said xorg starts again, but xrandr still does not recognize a second monitor. Do you have any idea on how to fix this?

scrouthtv

Member

Registered: 2019-10-15

Posts: 38

Re: [SOLVED] VirtualBox dual monitors

Okay I tried changing the graphics controller from the """""""recommended"""""""" VMSVGA to either VBoxVGA or VBoxSVGA and with those two, the second monitor at least appears in xrandr (tho still disconnected).

scrouthtv

Member

Registered: 2019-10-15

Posts: 38

Re: [SOLVED] VirtualBox dual monitors

Okay I don't even know how but I fixed it. I'm using the VBoxVGA driver and have both windows in fullscreen. Everything is working just as expected, I guess I'll never touch anything again