Storage system comprising nonvolatile semiconductor storage media

A storage system, comprising:

• a nonvolatile semiconductor storage medium;
• a storage part for storing logical-physical translation information, which is information denoting the corresponding relationship between a logical address and a physical storage area of the nonvolatile semiconductor storage medium;
• and
• a media controller, which is a controller coupled to the storage part and the nonvolatile semiconductor storage medium, wherein
• the logical-physical translation information includes:
• (A) information denoting corresponding relationships between multiple logical pages and multiple logical chunks forming a logical address space of the nonvolatile semiconductor storage medium;
• and
• (B) information denoting corresponding relationships between the multiple logical chunks and multiple physical storage areas,
• each logical page is a logical storage area conforming to a logical address range,
• each logical chunk is allocated to two or more logical pages of the multiple logical pages,
• two or more physical storage areas of the multiple physical storage areas are allocated to each logical chunk,
• the media controller is configured so as to identify, based on the logical-physical translation information, a physical storage area allocated to a logical chunk to which a logical page to which a data write-destination logical address belongs is allocated, and to write the data to this identified physical storage area, and
• the media controller adjusts the number of physical storage areas to be allocated with respect to each logical chunk.