I'm currently using Window 8 as host operating system and Ubuntu from a Virtual Box VHD. So my Ubuntu is running as virtual machine just fine with a few programs and development tools. But I now need to run in the Ubuntu environment some processes which require heavy processing and memory, so I would love to run them not in a virtual machine but as host operating system with the full resources available.

Is it possible to configure the machine to boot from that VHD I'm already using?

I have seen several posts on how to install a new Ubuntu with dual boot, configure dual boot inside a virtual machine, etc. I'v seen some MSDN post about booting from VHD, but that works only for Windows and it requires Windows Enterprise edition. I couldn't find anything for booting Ubuntu straight from a VHD. Is it possible? How?