Is there a way to set a higher resolution than 800x600 in VirtualBox without using Guest Additions?

Question

There is no shortage of questions about increasing the VirtualBox resolution to more than 800x600 with a Linux guest OS, but every time the proposed solution was "install Guest additions".

I want the VM to be as simple and as portable as possible, so I would prefer not to install "Guest additions" which seem to fail after each kernel upgrade, which have to be uninstalled before a VBox upgrade etc.

Is there a way to increase the resolution to something greater than 800x600 without Guest additions? Why can WinXP set 1024x768 without guest additions?

Answer 1

1. Add the host's native resolution as a VESA video mode:

   VBoxManage -q setextradata "CustomVideoMode1" "1280x1024x32"
   

2. Use the framebuffer device in your Xorg configuration file:

   Section "Device"
     # ...
     Driver "fbdev"
     # ...
   End Section
   

3. Use kernel mode setting with the boot option:

   video=uvesafb:mtrr:3,ywrap,1280x1024-32
   

However, performance will probably suffer horribly.

I think it would be better to add the VirtualBox repository to your package list, and then install DKMS which will recompile the modules when the kernel changes.

Another option is to use the Xvesa display server instead of Xorg; however, it is more limited (does not support XKB for instance).

Answer 2

Is there a way to increase the resolution to something greater than 800x600 without Guest additions?

No.

Why can WinXP set 1024x768 without guest additions

The default VGA driver sets the minimum resolution as 1024x768, AFAIK.