Patent ID: 8108486

Claim:
A remote copy system, comprising: a first storage system including a first storage controller and a first data volume, the first storage controller being configured to receive a write request from a first host associated with the first storage system and to store write data associated with the write request to the first data volume; a second storage system coupled to the first storage system, including a second storage controller and a storage area, the second storage controller receiving first data containing the write data to copy the stored data in the first data volume to the storage area; and a third storage system coupled to the second storage system, including a third storage controller and a second data volume, wherein the write request from the first host to the first storage system completes after the first data is received by the second storage system, and wherein the third storage controller is configured to receive the first data from the second storage system at a timing that is independent of a completion of processing of the write request from the first host associated with the first storage system.