This seems wrong to me. This was the state of the art ~3 years ago. Now, I feel like all of the machines should be provisioned already with an OS, and a basic image, and a orchestration system like CoreOS / Mesos / Docker should specialize them.
IMHO, requiring hardware, or the entire machine should be exception, not the rule.
IMHO, requiring hardware, or the entire machine should be exception, not the rule.