For environments that use Business Continuity Manager on two Teradata systems with identical content in the same data center, a single backup is enough for both systems. If systems are located in separate data centers, Teradata recommends maintaining backup copies in both locations. This protects against the loss of a data center and makes sure that a local backup is available if a restore is needed. This protects against transferring large amounts of data across the WAN joining the two data centers.