> 1. Someone has inadvertently modified the environment at some point. > A quick-fix or accidental change or an alteration in my playbook that > isn't cl

> 1. Someone has inadvertently modified the environment at some point. > A quick-fix or accidental change or an alteration in my playbook that > isn't clearly reflected in the running instance This will cause you comparable problems whether you're building from scratch or upgrading in place (iff you're using a tool like ansible). As noted by another responder, you've got a human problem there, not necessarily a technical one. > 2. Not all ansible modules are perfectly idempotent. It's a > fairly leaky abstraction. I've not used ansible, but have used a few other tools, so I understand how this is (easily) possible. As in other cases, the trick, of course, is to fix this. ; ) > 3. If you never build from scratch apart from the first time then > you're not really testing your automated deployment. The next time > you really need to build from scratch you might get a shock. Totally agreed. Your original post suggested the problem you had was with transitory data - evidently your concern is more to do with the ability to consistently and reliably rebuild a known and trusted environment. Persistent block storage won't help you with that.