
I tried changing the guest resolution with GUI, but a higher resolution was not listed. Unfortunately, xrandr failed to work for me. NOTE: I have VirtualBox 4.3.10 and Ubuntu 14.04 amd64 and guest additions don't work properly on it for me too, so I assume I will have to wait for next VBox version. Without the successful installation of guest additions, VirtualBox does not re-adjust guest resolution automatically, so graphics inside VM may look grainy/broken on bigger screen.

Was the installation of guest additions successful? You can check this by going to View menu and see if 'Auto-resize guest display' is enabled. Pressing right Ctrl + F will toggle full screen of that monitor.

If you manually resize the window on the host you'll only zoom on the image returned by the VM, so of course this gives a very bad image quality.Ĭhange the screen's resolution in the VM's configuration, either via the GUI, or directly via the command line with xrandr.įirst run xrandr with no arguments, it'll display all outputs (in this case they're just the virtual outputs emulated by VirtualBox). The window size is controlled by the VM's screen resolution.
