Storage subsystem and data management method of storage subsystem

A storage subsystem coupled to a host computer, the storage subsystem comprising:

• a storage device unit having a plurality of storage devices for storing data sent from the host computer;
• and
• a management unit for managing the storage device unit;
• wherein the management unit is caused to divide the storage device unit into storage areas of predetermined units;
• and
• select a data migration storage area when an IO access frequency from the host computer to the storage area exceeds a first access frequency threshold set in advance, migrate the data stored in the storage area to the storage area of the data migration destination, and block the storage area.

A data management method of a storage subsystem coupled to a host computer, the storage subsystem comprising:

• a storage device unit having a plurality of storage devices for storing data sent from the host computer;
• and
• a management unit for managing the storage device unit;
• wherein the management unit is caused to divide the storage device unit into storage areas of predetermined units and constitute a RAID group from two or more of said storage areas;
• select a data migration destination storage area when failure occurs to the storage area;
• and
• migrate data stored in the storage area where failure has occurred to the storage area of the data migration destination, and block the storage area where failure has occurred.