They started out with User Mode Linux actually, before Xen even existed.

dasmoth · on June 2, 2011

Indeed -- and stuck with it for quite some time. They were trialling Xen for some time, but I don't think they ever deployed it on a terribly large scale. Certainly, my VM went straight from UML to KVM.

pwaring · on June 3, 2011

I believe the management tools for Xen (or lack thereof) were the reason for using KVM instead. None of my machines (I have 7 or 8) have ever used Xen.

evangineer · on June 4, 2011

Thanks for the catch, I had forgotten that they were a UML shop.