Kabushiki Kaisha Toshiba

Toshiba Electronic Devices & Storage Corporation

Takumi Kakuya

Kenji Inoue

Michio Yamamoto

Hironori Kanno

Tetsuo Kuribayashi

Katsushi Ohta

Keiichi Yorimitsu

Seiji Toda

Nobuhiro Sugawara

Masami Tashiro

Hidekazu Masuyama

Kiyotaka Sasaki

Kimiyasu Aida

Takato Kuji

Yuji Karakawa

Masakazu Kitahara

Masataka Shitara

Isao Fujita

Hirotaka Iima

Satoru Adachi

According to one embodiment, a memory of a magnetic disk device includes a plurality of control queues respectively corresponding to a plurality of actuator systems. A controller receives a plurality of first commands from a host, and stores the plurality of first commands in one of the plurality of control queues. The controller generates a second command for internal processing, and stores the second command in a first control queue that stores a smallest number of commands among the plurality of control queues. The controller executes, for each of the plurality of control queues, processing one or more commands stored in one control queue of the plurality of control queues by using an actuator system corresponding to the one control queue among the plurality of actuator systems.

Magnetic disk device and method

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.

Disk device and disk device control method

According to one embodiment, there is provided a magnetic disk device including a magnetic disk, a storage unit, and a control unit. The magnetic disk includes a recording region. The storage unit is configured to store a value according to number of accesses to each of a plurality of regions obtained by dividing of the recording region of the magnetic disk in association with each of the plurality of regions. The control unit is configured to count a value according to the number of accesses to each of a plurality of regions in a count step unit that is a value determined according to an elapsed time from occurrence of a specific situation and is a value counted per unit access, and to update the value stored in the storage unit.

Magnetic disk device

According to one embodiment, any of a first process to perform a write retry to a write target track, a second process to perform the write retry and perform reading for data verification to an adjacent track, and a third process to perform the write retry and write data of the adjacent track to another track is executed based on a result of comparison between an offtrack amount and a plurality of different slice values.

Magnetic disk device and control method of magnetic disk

According to one embodiment, a read/write apparatus includes a receiver and a refresh module. The receiver receives a write command requesting a write to a magnetic disk. The refresh module refreshes, when a first area of the magnetic disk includes a second area corresponding to the write command, data written in a third area, the third area being an area obtained by excluding the second area from the first area.

Read/write apparatus and read/write method

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Ebina, Japan

Takumi Kakuya