Patent ID: 8566291

Claim:
A method of transferring de-duplicated data that is organized in virtual volumes to a target set of physical media comprising: forming an initial bitmap from the de-duplicated data on virtual volumes, the de-duplicated data on virtual volumes comprising a total number of discrete blocks; sorting the discrete blocks according to frequency of occurrence to form a revised bitmap to first include a plurality of most common discrete blocks; creating a physical volume map from the revised bitmap, the physical volume map associating each discrete block of the de-duplicated data on a virtual volume with an original physical volume and including a total set of original virtual volumes and a total number of data blocks; reviewing, from the physical volume map, an initial virtual volume of the virtual volumes contained on a corresponding original physical volume, to determine whether moving the initial virtual volume from its corresponding original physical volume to a different physical volume in the total set of original physical volumes reduces the total number of data blocks in the physical volume map without exceeding a total number of allowed blocks on the different physical volume; deleting the initial virtual volume from its corresponding original physical volume and adding the initial virtual volume to a different original physical volume to create a revised physical volume map including revised physical volumes; and writing the revised physical volumes to the target set of physical media using the revised physical volume map.