US Patent 9817768 Storage system and data storing method

Provided is a storage system including: a storage medium including a plurality of physical storage areas having an upper limit number of rewrites, and a medium controller that controls I/O (input/output) of data to/from the plurality of physical storage areas; and a storage controller connected to the storage medium, wherein when any of the physical storage areas is not allocated to a write destination logical storage area among a plurality of logical storage areas, the medium controller allocates a vacant physical storage area among the plurality of physical storage areas to the write destination logical storage area and writes write target data to the allocated vacant physical storage area, and the plurality of logical storage areas includes an available logical area group determined based on a relationship between an available capacity of a logical storage capacity and a rewrite frequency of the plurality of physical storage areas.