I have been working with VirtualBox and vagrant a lot today and found myself having to double check the VBoxManage CLI syntax a number of times. So I'm dumping a quick cheatsheet down to help remember it / help anyone else wanting to efficiently manage VBox VMs.
Start a VM
VBoxManage startvm "Name of VM" --type headless|gui
Forcibly Shutdown a VM
VBoxManage controlvm "Name of VM" poweroff
VBoxManage list vms
Unregister/delete a VM
VBoxManage unregistervm "Name of VM" --delete
Forward / Unforward Ports for SSH
Modifyvm must be only be used when VM is powered off, otherwise controlvm for running VMs.
VBoxManage modifyvm "VM name" --natpf1 "guestssh,tcp,,2222,,22" VBoxManage modifyvm "VM name" --natpf1 delete "guestssh"