According to one embodiment, a magnetic disk device configured to record data in a shingled-recording manner, wherein the device performs sequential write in a shingled-recording area on a magnetic disk such that data to be written in a write target track and data located in a one-forward track of the write target track are received on a volatile memory and then write with respect to the write target track is performed, and upon occurrence of an unexpected power cut, the device stores data unwritten in the shingled-recording area out of the data received on the volatile memory in a nonvolatile memory.

According to one embodiment, a magnetic disk device includes a disk, a write head, an adjustment unit, and a write processing unit. The adjustment unit adjusts each of a first adjustment value, a second adjustment value, and a third adjustment value. The write processing unit can select shingled magnetic recording and perform write processing based on the first to third adjustment values. When the number of the plurality of tracks of the band is t+1 and the number of unused sectors among the plurality of sectors of the band is e. The adjustment unit adjusts the first to third adjustment values to establish e<t.

According to one embodiment, a magnetic disk device includes a disk, a head, a volatile buffer memory, a nonvolatile memory, a main power supply, and a control unit. The control unit includes a write processing unit, a management unit, a data protection processing unit, a counter, and a determination unit. When the determination unit determines that a difference has reached a threshold, the management unit returns write data of the volatile buffer memory, which is original data of write data of a track in which a count value becomes a maximum value among tracks, to a protection target.

A magnetic media library drive includes a first disk medium fixed to a spindle, a first read-write transducer configured to operate on the first disk, a second read-write transducer configured to operate on a surface of a single removable second disk medium installed over the first disk, and electronic controller circuitry configured to cause: while the first transducer is servo-positioning from a master servo pattern from the first disk, the second transducer servo-writes a product servo pattern, based on the master servo pattern, to the surface of the second disk. The removable second disk can be removed, turned over, and secured to the spindle, whereby the self-servo writing procedure can be performed on the other side of the second disk based on the master servo pattern on the first disk.

According to one embodiment, in a disk device, a controller, when the rotation waiting time is present, increases an absolute value of a motor current in a fourth section in a second period in which a head is accelerated or decelerated, changes the absolute value of the motor current at a third average change rate in a fifth section after the fourth section in the second period, decreases the absolute value of the motor current at a fourth average change rate steeper than the third average change rate in a sixth section after the fifth section in the second period, and decreases the absolute value of the motor current at a fifth average change rate steeper than the fourth average change rate in a seventh section after the sixth section in the second period.

Various illustrative aspects are directed to a data storage device, comprising one or more disks; at least one actuator mechanism configured to position at least a first head proximate to a first disk surface and a second head proximate to a second disk surface; and one or more processing devices. The one or more processing devices are configured to: assign logical tracks to physical tracks of the disk surfaces such that a respective logical track comprises: at least a portion of sectors of a primary physical track, the primary physical track being on the first disk surface; and at least a portion of sectors of a donor physical track, the donor physical track being on the second disk surface. The one or more processing devices are configured to perform, using the first head and the second head, a data access operation with at least one of the logical tracks.

According to one embodiment, a disk device includes a magnetic disk, a magnetic head, a suspension, a ramp mechanism, a housing, and a screw. The suspension holds the magnetic head and moves between a load position and an unload position. The ramp mechanism includes a ramp member that holds the suspension at the unload position, and a cylindrical member with a through hole, being fixed to the ramp member. The housing includes a first support surface with a screw hole supporting the cylindrical member. The screw includes a screw head and a screw shaft fitted into the screw hole through the through hole. The screw holds the cylindrical member between the screw head and the first support surface. A contact area between the cylindrical member and the housing is set to larger than a contact area between the cylindrical member and the screw head.

A hard disk drive includes multiple disk media mounted on a spindle, where the outer diameter of each disk medium is offset from the inner diameter of the disk medium in a same direction along an axis of rotation of the spindle, and a load/unload ramp positioned, based on the offset, to align in correspondence with the outer diameters of the disk media. Thus, the curvature of irregular disk media, such as that associated with thinner and thinner disks, is mitigated by grouping similarly-characterized irregular disks together on a given spindle and compensating the ramp accordingly.

A computer-implemented method, a computer program product, and a computer system for repositioning operation on a tape medium based on dataset information. A computer system obtains dataset information of a dataset on a tape medium in a sync operation, where the dataset information includes positions of data in the dataset. A computer system sends the dataset information of the dataset to a host. In response to starting a repositioning operation, a computer system receives from the host the dataset information of the dataset. A computer system reads the dataset information of the dataset. A computer system repositions to a target on the tape medium, based on the dataset information of the dataset, where a tape drive refers to the dataset information and moves to a position immediately before the target.

Example control circuitry, data storage devices, and methods for determining wedge repeatable runout correction values for interleaved servo patterns in a data storage device are described. The data storage device may include multiple heads actuated over different surfaces of a data storage device and receive read signals from two different heads over two different surfaces in parallel. The servo wedges of the two surfaces may be offset to enable parallel learning of wedge repeatable runout correction values.