Patent ID: 8005800

Claim:
A data storage system for performing a copy operation, comprising: a control unit including a cache and coupled to an original source and an original target; an instant virtual copy process adapted to: perform an instant virtual copy operation from the original source to the original target, wherein the instant virtual copy operation performs a first background copy that copies blocks of data from the original source to the original target; and a fast reverse restore process adapted to: before the first background copy has completed, receive a fast reverse restore command indicating a new source and a new target, wherein the new source is the original target and the new target is the original source, wherein the fast reverse restore command restores original data that had been copied from the original source to the original target with the instant virtual copy operation before the first background copy has been completed by the instant virtual copy operation; perform a synchronous scan on the new target; update a new target structure associated with the new target using a new source structure associated with the new source, wherein updating the new target structure further comprises inverting indicators in the new source structure and copying the inverted indicators to the new target structure; and perform a second background copy from the new source to the new target using the updated new target structure.