Abstract: A magnetic disk device includes a disk has a first area in which data is written by first recording method such that a plurality of tracks are spaced from each other, and a second area written with data by second recording method such that adjacent tracks partially overlap, a head, and a controller. The controller is configured to control the head to write data to a track of the first or second area by the first or second recording method, and perform a retry operation when the data has not been written to the track successfully, and repeat the retry operation until the data is written successfully up to a predetermined number of times. When data is being written to a track of the first area, the retry operation is repeated up to a different number of times depending on a location of the track within the first area.

Abstract: According to one embodiment, a disk storage apparatus includes a disk having a storage area, a storage device storing management information, and a controller. The storage area includes a plurality of areas. The management information includes information indicative of a use priority or rank of each of the areas. The information indicative of the use priority or rank is set based on a quality index relating to a read operation or a write operation. The controller selects an area which is high in the use priority or rank and is usable, by referring to the management information, and executes the write operation on the selected area.

Abstract: According to one embodiment, a disk storage apparatus includes a disk having a storage area, a storage device storing management information, and a controller. The storage area includes a plurality of areas. The management information includes information indicative of a use priority or rank of each of the areas. The information indicative of the use priority or rank is set based on a quality index relating to a read operation or a write operation. The controller selects an area which is high in the use priority or rank and is usable, by referring to the management information, and executes the write operation on the selected area.

Abstract: According to one embodiment, a magnetic disk device includes a first magnetic head corresponding to a first disk surface; a second magnetic head corresponding to a second disk surface; a skip processor which performs skip processing to prevent selection of the second magnetic head when the first magnetic head performs writing; a write data saving unit which selects the second magnetic head based on a result of the detection of ae write environment, and writes write data to the second disk surface through the second magnetic head; and a write data write-back unit which selects the first magnetic head based on a result of the detection of the write environment, and writes the write data written to the second disk surface to the first disk surface through the first magnetic head.

Abstract: A head IC amplifies an output of a read head including MR elements and an ADC converts the amplified output into a digital value. When a CPU performs a head load operation to load a composite head including the read head onto a data area of a disk medium from a ramp, the CPU receives the output of the read head amplified by the head IC as a detection result of an external magnetic field applied to an HDD. The CPU determines whether the head load operation is performed or inhibited based on the received, amplified output of the read head, that is, the detection result of the external magnetic field applied to the HDD.

Abstract: A head IC amplifies an output of a read head including MR elements and an ADC converts the amplified output into a digital value. When a CPU performs a head load operation to load a composite head including the read head onto a data area of a disk medium from a ramp, the CPU receives the output of the read head amplified by the head IC as a detection result of an external magnetic field applied to an HDD. The CPU determines whether the head load operation is performed or inhibited based on the received, amplified output of the read head, that is, the detection result of the external magnetic field applied to the HDD.