Abstract: According to one embodiment, first setting information and second setting information are stored in a memory included in a magnetic disk device. The first setting information indicates a second track that is a first track set to be disused on the basis of a defect inspection among a plurality of first tracks included in a magnetic disk. The second setting information indicates a third track selected from one or more first tracks different from the second track. In a case where an access destination is a user area, the controller converts logical address information into physical address information while slipping the second track and the third track. In a case where an access destination is a system area, the controller converts logical address information into physical address information while slipping all of the first tracks other than the third track among the plurality of first tracks.

Abstract: According to one embodiment, a disk medium rotates in a first rotation state when access is given, and rotates in a second rotation state lower in rotation number than the first rotation state when access is not given. A controller receives, from a host device, a read command for reading first data stored in a first buffer, when the disk medium is in the second rotation state. The controller transmits the first data from the first buffer to the host device, without causing a shift into the first rotation state, and then shifts the disk medium into the first rotation state after completion of execution of the read command.

Abstract: According to one embodiment, a disk medium rotates in a first rotation state when access is given, and rotates in a second rotation state lower in rotation number than the first rotation state when access is not given. A controller receives, from a host device, a read command for reading first data stored in a first buffer, when the disk medium is in the second rotation state. The controller transmits the first data from the first buffer to the host device, without causing a shift into the first rotation state, and then shifts the disk medium into the first rotation state after completion of execution of the read command.

Abstract: According to one embodiment, a data storage apparatus includes a storage media and a controller. The controller is configured to execute a first process of reading or writing user data from or to the disk storage media which includes a plurality of recording areas, in accordance with a command requested via the host interface, the command including address information that are capable of specifying a recording area; to recognize a first area in which no user data is written, in a case of executing a second process different from the first process on the plurality of recording areas, without designating address information that are capable of specifying a recording area; and to execute the second process on a second area in which user data is written excluding the first area among the plurality of recording areas.

Abstract: According to one embodiment, A storage device includes a magnetic disk, a head, and a control unit. The magnetic disk includes a plurality of physical sectors having a first length. A logical block having a second length shorter than the first length, and a redundant area having a length of the difference between the first length and the second length are assigned for the physical sectors. The head reads the data from the physical sector of the magnetic disk. The control unit controls to change the second length of the logical block while maintaining the first length of the physical sector in response to reception of a change request for changing the second length of the logical block from a host.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a volatile memory, and a controller. The disk includes a save area and a user data area. The volatile memory includes a cache area and a cache management area. The cache area is used to store, as write cache data, write data specified by a write command to be written to the user data area. The cache management area is used to store management records for the write cache data. The controller writes write cache data indicated by the management record and not having been written to the user data area, to the save area in accordance with a synchronize command.

Abstract: According to one embodiment, A storage device includes a magnetic disk, a head, and a control unit. The magnetic disk includes a plurality of physical sectors having a first length. A logical block having a second length shorter than the first length, and a redundant area having a length of the difference between the first length and the second length are assigned for the physical sectors. The head reads the data from the physical sector of the magnetic disk. The control unit controls to change the second length of the logical block while maintaining the first length of the physical sector in response to reception of a change request for changing the second length of the logical block from a host.

Abstract: A disk device includes a recording medium having a plurality of recording surfaces, where each of the recording surfaces includes a system region for recording system data related to an operation of the disk device, and a controller configured to control recording of the system data in the system region. The controller is further configured to divide the system data to be recorded into a plurality of portions of divided data of the same size. The controller is further configured, after recording of a first portion of divided data in a first system region disposed on a first recording surface, to start recording a second portion of divided data in a second system region disposed on a second recording surface. The recording of the second portion of divided data is started after a switching time, during which switching from the first recording surface to the second recording surface transpires.

Abstract: A disk device includes a recording medium having a plurality of recording surfaces, where each of the recording surfaces includes a system region for recording system data related to an operation of the disk device, and a controller configured to control recording of the system data in the system region. The controller is further configured to divide the system data to be recorded into a plurality of portions of divided data of the same size. The controller is further configured, after recording of a first portion of divided data in a first system region disposed on a first recording surface, to start recording a second portion of divided data in a second system region disposed on a second recording surface. The recording of the second portion of divided data is started after a switching time, during which switching from the first recording surface to the second recording surface transpires.

Abstract: An information recording device includes a recording medium that includes a data area, and a controller that controls recording of data on the recording medium, wherein in response to a request for execution of formatting of the data area of the recording medium, the controller does not record data for the formatting in the data area and records format information about the formatting in a nonvolatile recording area that is different from the data area.

Abstract: According to one embodiment, a recording method includes: skipping a track by a skip amount in a skip region smaller than an overall recording region on a magnetic recording medium by using an extra region that is unnecessary for securing a storage capacity to be provided by a storage device, the extra region being on the recording surface of the magnetic recording medium; and recording data while skipping the track in the skip region, wherein the skip region is set to a region in which a track to be recorded on the magnetic recording medium is expected to influence an adjacent track in accordance with at least one of a condition and a state of the storage device.

Abstract: A magnetic disk device performs test write before storing system information to check the state of each head. The magnetic disk device then stores test write results in a test-write-result table of a RAM. The magnetic disk device then determines whether the number of defective heads is equal to or greater than a predetermined number. When the number of defective heads is equal to or greater than the predetermined number, the magnetic disk device suspends the process of storing the system information. When the number of defective heads is less than the predetermined number, the magnetic disk device refers to the test write results stored in the test-write-result table and performs write only with a head determined as normal.

Abstract: A magnetic disk device performs test write to check the state of each of heads before system information is stored in a disk and, based on the result of the test write, stores the system information sequentially with the heads from one in good state. After a predetermined time has elapsed, the magnetic disk device suspends the process of storing the system information.

Abstract: A magnetic disk device performs test write on a test cylinder to check the state of each head before system information is stored in disks. The magnetic disk device then determines the state of each head based on the test write results stored in a test-write-result table. When a head is defective, the magnetic disk device notifies a host of the possibility of the occurrence of a timeout as a fault prediction.

Abstract: A storing unit stores initial parameters indicating initial values of control parameters in a first storage medium in association with first update parameters obtained by modifying the initial parameters. A difference detecting unit compares, when second update parameters are stored in a second storage medium, the initial parameters with the second update parameters, and detects a parameter that is different between the initial parameters and the second update parameters. An initialization unit initializes the first update parameters based on a result of detection by the difference detecting unit.

Abstract: In a disk storage apparatus, an micro processing unit (MPU) as an upper unit calculates a positional relationship between a head section and storage disks using disk management data indicating the positional relationship of servo information among the storage disks to complete a servo lock based on the result of calculation. The servo lock can thereby be executed at high rate without waiting for a disk controller as a lower unit to complete a servo lock.

Abstract: In a disk storage apparatus, an micro processing unit (MPU) as an upper unit calculates a positional relationship between a head section and storage disks using disk management data indicating the positional relationship of servo information among the storage disks to complete a servo lock based on the result of calculation. The servo lock can thereby be executed at high rate without waiting for a disk controller as a lower unit to complete a servo lock.