Patent ID: 8332612

Claim:
An apparatus for reclaiming storage space identified as no longer in use, the apparatus comprising: a virtual logic unit (vLUN) layer constructed and arranged to be part of the input/output (I/O) path of a computer system, the vLUN configured to provide a plurality of logical chunk addresses (LCAs) to layers disposed above it; a thinly provisioned mapped logical unit (mapped LUN) layer disposed below and in operable communication with the vLUN layer, the thinly provisioned mapped LUN being in operable communication with a pool of storage units that provide, as requested, storage space to the thinly provisioned mapped LUN, wherein the mapped LUN is associated with a plurality of physical chunk addresses (PCAs), each PCA configured to provide physical storage for a respective chunk of data; and a data reduction engine in operable communication with the vLUN, the data reduction engine configured to: perform a data reduction process on a first logical chunk of data stored in the vLUN at a first LCA and associated with a first PCA; remap the first LCA to a second PCA in a second region of the mapped LUN such that a first PCA in a first region of the mapped LUN is no longer required for storage of a first logical chunk of data and is therefore a first unneeded chunk, wherein: the first region on the mapped LUN comprises a set of first PCAs, each first PCA being allotted to provide physical storage for a respective first chunk of data stored at a single first corresponding LCA in the vLUN; and wherein the second region of the mapped LUN comprises a set of second PCAs, each second PCA being allotted to provide physical storage for a respective second chunk of data, where the second chunk of data corresponds to data that is associated with at least two LCAs; and instruct the thinly provisioned mapped LUN to deallocate the first PCA associated with the first unneeded chunk.