[oliao]

I think the point made here is quite interesting: instead of relying on (puppet, chef,...) to do the "deltas", always generating the whole system from scratch. This has a couple of advantages:

* You make sure everything is automated

* You can always trust the resulting system works; if it were to be built from scratch

[brudgers]

Immutable hardware requires [an analogous] garbage collector.

Most of the next machine would have the same state as the old one:

  ; Machine -> Machine
  ; Makes the next machine
  (define (next-machine m)
    (make-machine
      (machine-name m) 
      (machine-cpu m)
      (machine-storage m)
      (update-os CURRENT-OS)
      (machine-applications m)))