This type of scenario is known as Disaster Recovery. In order to truly diffuse a data center outage, we need backups of every major database server, and even minor servers. The reasoning is simple: we don't know how long we have to operate at reduced capacity. At that point, even non-critical reporting services still need analogs, otherwise business decisions that depend on activity analysis may not be possible.
We only really need half the amount of database servers, as most disaster recovery scenarios are severe enough for raised alertness, reduced refresh times, manually extended queue timeouts, and more. Not only is this less expensive than having a copy of every server as the primary data center, but it also encourages ...
