Patent ID: 8135674

Claim:
A system for managing images of a storage object, the system comprising: a computer system including a processor and memory, the computer system configured for: generating a first image of the storage object; receiving new data relating to changes to the storage object occurring after the first image is generated; generating a first clone comprising a reference to the first image and the new data; generating a second image of the first clone; and deleting the first clone and the first image without first deleting the second image, the first image comprising a backing image of the first clone and the second image whereby a dependency exists between the first clone and the first image and a dependency exists between the second image and the first image based on the reference to the first image contained in the first clone, wherein: the first image comprises an associated reference counter, the first image being locked from deletion if the reference counter is greater than zero; the reference counter of the first image is incremented upon generating the first clone; the reference counter of the first image is not incremented upon generating the second image; and deleting the first clone decrements the reference counter of the first image to zero, whereby the first image is unlocked from deletion and allows the first image to be deleted without deleting the second image.