It was possible and still should be. I used his setup a lot while teaching a network program at a local college here covering both windows and linux servers and desktops OS / config / etc, etc and it worked great! Ran dl from ram with persistence only back to the hard drive (booting from usb disk) with no issues. I had about 2 GB of ram available in the machines I was using in the classrooms and did notice they were slower than the ones I was using to build and prototype the system on, which had 4 otherwise works exactly as expected but so did KVM at that time and KVM seemed to be just a little less resource hungry with better linux support .
I hope this helps.