Patent ID: 8918378

Claim:
A machine implemented method, comprising: generating, by a storage server a new extent identifier for cloning a portion of a source extent identified by a source extent identifier stored at a source data structure; wherein the source extent includes a group of contiguous blocks for storing a data container and the source data structure includes a length value providing a length of the source extent, an offset value that refers to a distance in blocks from a known location of the data container and a reference count value that provides a number of data containers that reference the source extent identifier; and updating a data structure for a cloned version of the data container for storing the new extent identifier that points to the source extent identifier; wherein the updated data structure includes an extent length value that is different from the length value of the source data structure and an offset value that is different from the offset value of the source data structure; and wherein when a cloning request is to clone the entire source extent then the source extent identifier is also used for the cloned version and a reference count value of the data structure for the cloned version indicates that the source extent identifier is referenced by both the data container and the cloned version.