Abstract: In a storage system, a controller prevents the same chunk data from being stored in a storage device in an overlapped manner, on the basis of data block information showing an association of each data block and a plurality of chunk data configuring each data block, chunk group information showing an association of each chunk data not to be overlapped and a chunk group which each chunk data belongs to, and reference data block information showing an association of each chunk group and a data block having any chunk data belonging to each chunk group as constituent elements.

Abstract: A storage system divides a file into large chunks, executes primary deduplication processing (a first step in deduplication processing) to perform deduplication on the large chunks regardless of a file format, divides at least one large chunk into small chunks, and does not execute secondary deduplication processing (a second step in the deduplication processing) to perform deduplication on the small chunks when the file format satisfies a predetermined condition but executes the secondary deduplication processing when the file format does not satisfy the predetermined condition.

Abstract: In a storage system, a controller prevents the same chunk data from being stored in a storage device in an overlapped manner, on the basis of data block information showing an association of each data block and a plurality of chunk data configuring each data block, chunk group information showing an association of each chunk data not to be overlapped and a chunk group which each chunk data belongs to, and reference data block information showing an association of each chunk group and a data block having any chunk data belonging to each chunk group as constituent elements.