Note: VirtualBox Auto-Resizing Screen Resolution

I tried Manjaro - KDE. After installing it in a VM I couldn’t change the screen resolution. I searched online and realized I had never set it up properly.

Writing down what I did.

Normal Process

• Install a Manjaro VM.
• Set up proxy. See Note: Linux Proxy Settings.
• Install VirtualBox Guest Additions. See ArchWiki - VirtualBox - 2.2 Install the Guest Additions.

1
sudo pacman -S virtualbox-guest-utils
2
sudo pacman -S xf86-video-vmware
3
sudo pacman -S linux-lts-headers

• The first command asks you to choose a module. I didn’t see virtualbox-guest-modules-arch mentioned in the wiki, so I picked 12.
  
• Set VirtualBox to auto-resize display. Reference: Manjaro guest on VirtualBox not able to get the full resolution
  • Shut down the VM.
  • VM settings -> Display -> Graphics Controller -> choose VBoxVGA, save.
    
  • Boot the VM, resize the window a bit, then the screen goes black.
  • Press Ctrl Alt F2 to open another tty console, log in.
  • sudo mhwd -r pci video-vmware
  • reboot

After that, you can freely change the VM window size.

(Among Manjaro’s three desktop environments: xfce is the lightest, installs fast, but doesn’t look as nice. KDE and Gnome both got stuck at 93% Misc postinstall configurations for more than 10 minutes, and I almost thought my PC was broken.)

A Simpler (Slightly) Method

I tried choosing VBoxVGA from the start while creating/installing the VM.
Then the resolution auto-resized right away without needing the console steps.
Shared clipboard worked, but drag-and-drop didn’t; you still need Guest Additions for that.

Tips: Switching Back To The Host

Alt Tab switches from host to guest, but I never knew how to switch back.
Today I finally remembered to look it up.
Method: press the right Ctrl once to release the keyboard capture; then Alt Tab works on the host again.
Ref: How to switch between host and guest OSes in virtual box

2020/01/04 update
Tried to set up file sharing, but failed. It seems the vboxsf module is missing.
Checking vboxservice process: line 7 (code=exited, status=1/FAILURE) is red.

1
$ systemctl status vboxservice.service
2
● vboxservice.service - VirtualBox Guest Service
3
   Loaded: loaded (/usr/lib/systemd/system/vboxservice.service; enabled; vendor preset: disabled)
4
   Active: active (running) since Sat 2020-01-04 18:06:58 CST; 3s ago
5
  Process: 1522 ExecStartPre=/usr/bin/modprobe vboxguest (code=exited, status=0/SUCCESS)
6
  Process: 1523 ExecStartPre=/usr/bin/modprobe vboxvideo (code=exited, status=0/SUCCESS)
7
  Process: 1524 ExecStartPre=/usr/bin/modprobe vboxsf (code=exited, status=1/FAILURE)
8
 Main PID: 1525 (VBoxService)
9
    Tasks: 9 (limit: 4915)
10
   Memory: 1.4M
11
   CGroup: /system.slice/vboxservice.service
12
           └─1525 /usr/bin/VBoxService -f

modinfo vboxguest and modinfo vboxvideo both show module info, but modinfo vboxsf can’t find the file. Strange.
Still not solved.