Patent ID: 8220000

Claim:
A storage system comprising: a plurality of memory devices configuring a plurality of logical units; a processor managing a plurality of files stored in the respective logical units, and monitoring an input/output load for each of the plurality of logical units; a memory storing a file management table for managing a predetermined priority for each of the plurality of logical units, the input/output load for each of the plurality of logical units, and a file management execution ranking for each of the plurality of logical units; one or more block input/output interfaces; and one or more file input/output interfaces, wherein the file management execution ranking indicates an order of managing the files stored in the plurality of logical units, wherein the file management execution ranking is determined by arranging the plurality of logical units in order of the predetermined priority, and then further arranging the plurality of logical units based on the input/output load of each of the plurality of logical units, wherein the processor measures the input/output load of each of the plurality of logical units and determines whether the input/output load of each of the plurality of logical units is less than a predetermined threshold, wherein the logical units having an input/output load that is less than the predetermined threshold are first logical units, and the logical units having an input/output load that is greater than the predetermined threshold are second logical units, wherein the first logical units are arranged in order of the predetermined priority, and after the first logical units are arranged in order of the predetermined priority, the second logical units are arranged in order of the predetermined priority, the first logical units being arranged higher in priority than the second logical units, wherein the processor executes managing the files stored in the plurality of logical units in order of the determined file management execution ranking, wherein one or more of the plurality of logical units are provided to a SAN (Storage Area Network) client via the one or more block input/output interfaces, and another or more of the plurality of logical units are provided to a NAS (Network Attached Storage) client via the one or more file input/output interfaces, and wherein, if the load in one of the one or more file input/output interfaces reaches or exceeds a predetermined threshold, the one file input/output interface mounts the plurality of logical units via another of the one or more file input/output interfaces or the one or more block input/output interfaces, and controls the file management.