Patent ID: 7089383

Claim:
A system for redundantly backing up data, comprising: a first storage facility controlled by a first state machine having a finite number of states, each state of the first state machine having a set of allowed operations, and the first state machine including at least one state for controlling the first storage facility to operate as a primary storage facility, the primary storage facility being for storing and updating a primary copy of the data; and a second storage facility coupled to the first storage facility wherein the second storage facility is controlled by a second state machine having a finite number of states, each state of the second state machine having a set of allowed operations, and the second state machine having at least one state for controlling the second storage facility to operate as a secondary storage facility, the secondary storage facility being for storing data that is a redundant copy of the primary copy, the redundant copy updated by updates forwarded from the primary storage facility, and at least one state for controlling the second storage facility to operate as the primary storage facility, wherein prior to a failover event, the first storage facility operates as the primary storage facility and the second storage facility operates as the secondary storage facility and after the failover event, the second storage facility operates as the primary storage facility, and wherein the failover event comprises a communication traffic condition in which a greater portion of request traffic originates closer to the second data storage facility.