Patent ID: 8156306
Filing Date: 2012-04-10
Classification: G06F

Abstract:
1. A system to reclaim space identified as no longer in use, the system comprising: a virtual logic unit (vLUN) layer that corresponds to one of a plurality of layers in an input/output (I/O) path of a computer system, the vLUN providing a plurality of logical chunk addresses (LCAs) to layers disposed above it in the I/O path, such that the LCAs in the vLUN are the only LCAs visible to layers above the vLUN; a thinly provisioned mapped logical unit (mapped LUN) layer disposed below the vLUN in the I/O path and being in operable communication with the vLUN, the thinly provisioned mapped LUN being in operable communication with a pool of storage units that provide, as requested, storage to the thinly provisioned mapped LUN, the thinly provisioned mapped LUN having associated therewith a storage extent of a predetermined size, the storage extent defining a minimum size of storage that the thinly provisioned mapped LUN can be directed to allocate or deallocate from the pool, 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; a mapping layer disposed between and in operable communication with the vLUN and the thinly provisioned mapped LUN layers, the mapping layer defining a layout of the thinly provisioned mapped LUN that helps improve the efficiency of input/output (I/O) access to the mapped LUN, the layout comprising: a data reduction engine in operable communication with the mapping layer, the data reduction configured to: