Patent ID: 8782369

Claim:
A data storage apparatus comprising: a processor; a first data storage device connected to the processor, configured to store a reserve space table of unmapped data blocks; and a second data storage device connected to the processor, wherein: the first data storage device has a relatively faster access time than the second data storage device; the reserve space table is configured to identify discrete portions of the first data storage device and discrete portions of the second data storage device; and the processor is configured to: transfer data from a discrete portion of the second data storage device to a discrete portion of the first data storage device identified in the reserve space table; after transferring data from the discrete portion, add a location of the discrete portion of the second data storage device to the reserve space table and remove a location of the discrete portion of the first data storage device from the reserve space table; transfer data from a plurality of discrete portions of the first data storage device to a plurality of discrete portions of the second data storage device; after transferring data from the plurality of discrete portions add a plurality of locations, each associated with one of the plurality of discrete portions of the first data storage device to the reserve space table and remove a plurality of locations, each associated with one of the plurality of discrete portions of the second data storage device from the reserve space table.