I need to virtualise Ubuntu 24/7 on my Mac. Is there a lite virtualisation piece of software that allows me to run it discretely? I do not want an interface... I will manage via SSH... I have been using VirtualBox but it always insists on having a window open... can I run a guest OS as a service?? VMWare server looks suitable but it's not available for the Mac... :-(
VirtualBox is still your friend. You can launch the VM's headless.
Try running the following in Terminal.app:
VBoxHeadless --help
It seems that you can also do:
VBoxManage startvm <vmname> --type headless