Patent ID: 8521978

Claim:
A storage apparatus comprising: an I/O processing part which writes data to a physical drive or reads data from the physical drive in response to a data write request or a data read request transmitted from an external device; a storage area management part which implements a Thin Provisioning function by providing the external device with a storage area of the physical drive in units of a virtual volume which is a logical storage area, and by allocating a storage area of the physical drive managed as a storage pool to a logical page in units of a physical page that is a management unit of the storage area of the physical drive, the logical page being a management unit of a storage area of the virtual volume; a tier arrangement processing part which classifies the physical drive into tiers, which manages an access frequency of each of the logical pages, and which, when the access frequency of the logical page satisfies a predefined condition, allocates a migration destination physical page that is the physical page belonging to a tier different from a tier to which a migration source physical page that is the physical page currently allocated to the logical page belongs, and performs tier arrangement processing to replicate data stored in the migration source physical page to the migration destination physical page; and a replacement processing part which receives a request to replace the physical drive in units of a physical device that is a physical storage device including a storage area of the physical drive, and performs replacement processing for the physical drive by replicating data stored in the physical device of a replacement source to the physical device of a replacement destination, and by reallocating a storage area of the physical device of the replacement source to the storage area of the virtual volume, wherein the storage apparatus stores a designation of a tier arrangement processing mode which is a processing mode of the tier arrangement processing, and in performing the replacement processing, when a first processing mode is designated as the tier arrangement processing mode, the replacement processing part cancels start of the tier arrangement processing, and starts the replacement processing.