Wikimedia's operations team go through a full-datacenter failover regularly. That is, once every 6 months or so. It takes several hours of intense all-hands-on-

Wikimedia's operations team go through a full-datacenter failover regularly. That is, once every 6 months or so. It takes several hours of intense all-hands-on-deck operations. They do this repeatedly in order to be sure that all of the procedures are practiced and documentation is well maintained.