I am on a Mac. I installed docker and ran the terminal. It starts the virtual machine. Now I want to install VirtualBox but the installation program complains that there is a virtual machine running that I must stop first. I exited the terminal and it said things about saving stuff but the VirtualBox installation program still says I need to stop a virtual machine. How do I do that? Since I don't have Virtualbox installed yet I don't know how to access it...
And now I feel silly, but the command is:
docker-machine stop