This note to self explains how to remotely start an existing Oracle VM VirtualBox machine over ssh and find its IP address.
Step 1: once you’ve ssh-ed into the host machine on which you would like to run a VirtualBox virtual machine, start the virtual machine by typing in terminal
$vboxmanage startvm UbuntuVM --type headless
In the above UbuntuVM is the name of the virtual machine that you want to start.
Step 2: to find out the IP address of the VM
$vboxmanage guestproperty enumerate Ubuntu12.04.3 | grep IP
Et voila! Now you can ssh into your VM.