US Patent 9063967 Performing copies in a storage system

A system and method for performing copy offload operations. When a copy offload operation from a first volume (pointing to a first medium) to a second volume (pointing to a second medium) is requested, the copy offload operation is performed without accessing the data being copied. A third medium is created, and the first medium is recorded as the underlying medium of the third medium. The first volume is re-pointed to the third medium. Also, a fourth medium is created, the second volume is re-pointed to the fourth medium, and the second medium is recorded as the underlying medium of the targeted range of the fourth medium. All other ranges of the fourth medium have the second medium as their underlying medium.