Ever wanted to change the resolution of a virtual machine (in VirtualBox) and couldn't find the resolution you want in the settings? You can easily do this using VBoxManager, a command line tool that lets you control various aspects of your virtual machines.
There's one thing you need to know before trying this: you need to install the VirtualBox Guest additions before trying to set a high resolution or else it won't work.
To change the resolution of any running virtual machine, look for its name in VirtualBox Manager VM list and run the following command:
VBoxManage controlvm "MACHINE NAME" setvideomodehint WIDTH HEIGHT BPP
Replacing "MACHINE NAME", WIDTH, HEIGHT and BPP (bits per pixel - 24 or 32) with your values.
In my example, the machine name is "10.10":
So the command to change the resolution to 1280x800 would be:
VBoxManage controlvm "10.10" setvideomodehint 1280 800 32
Thanks to Linuxundich.de for the info!