Patent ID: 7430646

Claim:
A method of swapping a primary group at a first data center and a synchronous backup group at a second data center where triangular asynchronous replication is being provided using the primary group, the synchronous backup group, and an asynchronous backup group at a third data center, the method comprising: halting work at the first data center; transferring pending mirrored data from the first data center to the third data center; creating a data mirroring relationship between at least one storage volume at the second data center and at least one storage volume at the third data center; reversing a data mirroring relationship between the at least one storage volume at the first data center and at least one storage volume at the second data center; and resuming work at the second data center, wherein writes to the at least one storage volume at the second data center are mirrored synchronously to the at least one storage volume at the first data center and are mirrored asynchronously to the at least one storage volume at the third data center.