By and large, if you manage physical, owned infrastructure the same way you manage cloud resources. That is: automated configuration, monitoring, and deployment. The vast majority of the time it's the same process. You just need to make sure that your instrumentation is sufficient to notice when things aren't running correctly and remove machines from service until someone can figure out what happened. This could be in the form of an outside tech or in house support. Either way, at clusters of this size a loss of one, or even 5 machines should not be the difference between everything working and a colossal systems failure.