Patent ID: 7318136

Claim:
A system for performing data migration, comprising: a first storage system including a first storage controller and a first data volume configured with a plurality of physical storages therein, the first storage controller being configured to receive a write request from a host computer and to store write data associated with the write request to the first data volume; and a second storage system coupled to the first storage system, including a second storage controller and a second data volume configured with a plurality of physical storages therein, the second storage controller being configured to receive a copy of the write data for copying the write data stored in the first data volume to the second data volume based on copy configuration information, said copy configuration information including a relationship between the first data volume and the second data volume; wherein a third storage system coupled to the first and second storage systems receives the copy configuration information from the first storage system and maps a virtual volume to the first data volume so as to present the first data volume via the virtual volume to the host computer, and then, based on the received copy configuration information, sends to the second storage system a copy of write data associated with write requests received from the host computer directed to the virtual volume.