Google might not run the vast majority of their services on VMs, but they do use virtualization (Xen AFAIK). They even developed a cluster management tool for

Google might not run the vast majority of their services on VMs, but they do use virtualization (Xen AFAIK). They even developed a cluster management tool for Xen/KVM: http://code.google.com/p/ganeti/ http://code.google.com/p/ganeti/