Patent ID: 8180985
Filing Date: 2012-05-15
Classification: G06F,H04L

Abstract:
1. A storage switch for controlling reading and writing of data from and into a storage area, the storage switch comprising: a first bitmap generator for generating a first bitmap including a plurality of index bits which render the storage area to be partitioned into a plurality of regions each having a predetermined partition size and being associated with each of the index bits of the first bitmap; a controller for controlling copying of data in a part of the regions to another part of the regions; a first modifier for modifying at least one of the index bits associated with at least one of the regions having undergone a copying; a second bitmap generator for generating a second bitmap including a plurality of index bits which render the storage area to be partitioned into a plurality of sub-regions each having a partition size smaller than the predetermined partition size and being associated with each of the index bits of the second bitmap, the controller controlling writing of data into at least one of the sub-regions addressed by a write request from the exterior; a second modifier for modifying at least one of the index bits corresponding to the at least one sub-regions addressed by the write request from the exterior; and a merging controller for controlling to generate a third bitmap including a plurality of index bits which render the storage area to be partitioned into a plurality of sub-regions each having the same size as the partition size, the merging controller, when the writing of data is performed during the copying of data, modifying a part of the index bits in the third bitmap corresponding to a part of the index bits of the first bitmap modified by the first modifier on account of the copying of data performed before the writing of data, and merging the second bitmap modified by the second modifier and the third bitmap modified by the merging controller; the controller resuming copying of data of any sub-regions on the basis of the merged bitmap.