US Patent 8200922 Storage system snapshot assisted by SSD technology

A method and apparatus for taking a snapshot of a storage system employing a solid state disk (SSD). A plurality of mapping tables in the SSD store data needed to create a one or more point in time snapshots and a current view of the SSD. In response to a write command, the SSD executes its normal write process and updates its mapping tables to indicate the current view of the SSD and additionally retains the original data in a table of pointers to the original data, as the snapshot of an earlier state of the SSD. In the preferred embodiment, the innate ability of SSDs to write data to a new location is used to perform a point-in-time copy with little or no loss in performance in performing the snapshot.