Patent ID: 8788752
Filing Date: 2014-07-22
Classification: G11B

Abstract:
1. A storage apparatus comprising: a storage device for storing data from a host apparatus; a written state bit map memory that stores a written state bit map that includes bits each allocated to one of partial areas of the storage device for storing write management information indicating whether written data is present in a partial area of the storage device that is allocated to one of the bits; a bit map management section, when data is written into a partial area of the storage device in response to a write request from the host apparatus, that sets a value indicating that the data is written into the partial area to a bit allocated to the partial area in which the data is written; a patrolling process section for performing a patrolling process on the partial areas of the storage device on the basis of the write management information stored in the written state bit map memory; and a patrol object bit map memory that stores a patrol object bit map includes bits each allocated to one of the partial areas for storing patrol object information indicating whether partial areas allocated to the bit is a patrol object, wherein the bit map management section copies the write management information to the patrol object information prior to an execution of a patrolling process, and the patrolling process section performs the patrolling process on the partial area of the storage device corresponding to a bit of the patrol object bit map memory that stores the patrol information indicating the patrol object, wherein the bit map management section sets a value indicating the patrol object to a second bit of three successive bits stored in the patrol object bit map memory, in the case that a value indicating the patrol object is stored to a first bit of the three successive bits, a value not indicating the patrol object is set to the second bit of the three successive bits, and a value indicating the patrol object bit map memory is set to a third bit of the three successive bits.