Reusable content addressable stores as building blocks for creating large scale storage infrastructures

Abstract

Techniques are described for using chunk stores as building blocks to construct larger chunk stores. A chunk store constructed of other chunk stores (a composite chunk store) may have any number and type of building block chunk stores. Further, the building block chunk stores within a composite chunk store may be arranged in any manner, resulting in any number of levels within the composite chunk store. The building block chunk stores expose a common interface, and apply the same hash function to content of chunks to produce the access key for the chunks. Because the access key is based on content, all copies of the same chunk will have the same access key, regardless of the chunk store that is managing the copy. In addition, no other chunk will have that same access key.