US Patent 7593973 Method and apparatus for transferring snapshot data

A method, device, and system are provided for the efficient transfer of snapshot data during a snapshot delete action. The snapshot data to be deleted may have an older version of the same snapshot and that older snapshot may need to access the data from the newer snapshot. Instead of copying all of the snapshot data of the snapshot that is being deleted to the older snapshot, only pointers to the data are copied to the older snapshot. Additionally, snapshot data can be accessed for read functions or the like while the snapshot pointers are being copied to the older snapshot.