I sometimes run Ubuntu inside a VirtualBox virtual machine. In this Ubuntu, to switch from graphical window manager to the first virtual console, press
Host + F1. By default, the
Host key in VirtualBox is assigned to
Right Ctrl key. So, I press
Right Ctrl + F1. To get back to graphical window manager, switch to the 7th virtual console:
Right Ctrl + F7.
Tried with: VirtualBox 4.3.20