US Patent 7640409 Method and apparatus for data migration and failover

Method and apparatus for data migration are described herein. In one embodiment, in response to data received from an application to be written to a first storage volume, the data is written to the first storage volume and a second storage volume substantially concurrently. When the first and second storage volumes are synchronized, a switchover is performed from the first storage volume to the second storage volume, such that subsequent data received from the application is written to the second storage volume, where writing the data to the first and second storage volumes and the switchover are performed without knowledge of the application. Other methods and apparatuses are also described.