Intro
This is a list of command line commands I've found useful.
Use these commands to eg ssh into a server and start a VM there.
I use this to start a remote virtualized pihole instance on my main server from my workstation.
The list
In no particular order.
Resize vdi-file
# vboxmanage modifyhd "/full/path/to/virtualdisk.vdi" --resize 40960
List VMs
# vboxmanage list vms
List running VMs
# vboxmanage list runningvms
"Ubuntu 16.04 Server x64 LTS" {bc9819d4-c39b-47d0-ac27-5cda8ab57419}
Use the UID between the curly brackets to start a VM headless, see below.
Shut down a VM
# vboxmanage controlvm "vm" poweroff
Start a VM with GUI
# vboxmanage startvm "vm" --type gui
Start a VM headless (no GUI)
# vboxheadless --startvm bc9819d4-c39b-47d0-ac27-5cda8ab57419 &
More to come...
Sources
The interweb