Well, physically, you really need three independent machines. Which means three copies of the file, three processes, three verifications, and so on, and a way f

Well, physically, you really need three independent machines. Which means three copies of the file, three processes, three verifications, and so on, and a way for those processes to communicate with each other and "vote". Then you run into the problem of definition - is a cluster a quine? Note that most of the "primordial bit flip" problems go away if you make N >> 3 and design each machine to "fail fast".