US Patent 9092151 Managing deduplication of stored data

In one aspect, in general, a method for managing data includes receiving, at a data deduplication engine of a computer system, data to be stored in a data storage system, computing a first value corresponding to at least one portion of the received data, determining that the first value matches a second value stored in a collection of identifiers, each identifier corresponding to a particular portion of data stored in the data storage system, each identifier comprising a computed value corresponding to the particular portion of data and including metadata indicating a location where the particular portion of data is being stored in the data storage system, and based on the determination that the first value matches a second value stored in the collection of identifiers, reallocating one or more physical locations from corresponding one or more virtual locations to different respective one or more virtual locations.