A data storage device is disclosed comprising a first disk comprising a first disk surface, a second disk comprising a second disk surface, an elevator actuator configured to actuate a head along an axial dimension relative to the first and second disks, a radial actuator configured to actuate the head radially over the first disk surface or the second disk surface, and a position sensor configured to generate a sinusoidal sensor signal representing a position of the head along the axial dimension. A crashstop_offset along the axial dimension is measured from a crashstop position of the elevator actuator to a zero crossing of the sinusoidal sensor signal.

A method for writing data in a disk drive having actuators each controlling arms extending over disk surfaces, including: receiving a write command from a host; receiving from the host data; dividing the data into data blocks; determining: a first surface from the disk surfaces where data is written by a first head of an arm controlled by a first actuator of the actuators; and a second surface from the disk surfaces where data is written by a second head of an arm controlled by a second actuator of the actuators; determining storage blocks of each of the first and the second surface; and writing first data blocks of the divided data blocks to the determined storage blocks of the first surface using the first head while writing second data blocks of the divided data blocks to the determined storage blocks of the second surface using the second head.

According to one embodiment, a magnetic disk device includes a base that includes a bottom wall and side walls standing along a circumference of the bottom wall, a housing that includes a cover facing the bottom wall and closing the base, an actuator assembly that is housed inside the housing and is rotatable around a rotation axis, a head movably supported by the actuator assembly, a control circuit board provided outside of the housing, a first sensor disposed on the control circuit board, and a second sensor disposed inside the housing.

A PZT microactuator such as for a hard disk drive has a restraining layer bonded on its side that is opposite the side on which the PZT is mounted. The restraining layer comprises a stiff and resilient material such as stainless steel. The restraining layer can cover most or all of the top of the PZT, with an electrical connection being made to the PZT where it is not covered by the restraining layer. The restraining layer reduces bending of the PZT as mounted and hence increases effective stroke length, or reverses the sign of the bending which increases the effective stroke length of the PZT even further. The restraining layer can be one or more active layers of PZT material that act in the opposite direction as the main PZT layer. The restraining layer(s) may be thinner than the main PZT layer.

A data storage device is disclosed comprising a head actuated over a disk comprising servo data for defining a plurality of data tracks. A plurality of zones are defined for the disk, wherein each zone comprises a plurality of the data tracks. Position error signal (PES) repeatable runout (RRO) values are generated based on the servo data in a first zone, and data sector squeeze RRO values are generated based on data segments in the first zone. A first data track format for the first zone is generated based on the PES RRO values, and a second data track format is generated for the first zone based on the data sector squeeze RRO values.

According to one embodiment, a magnetic disk device includes a magnetic disk including a plurality of tracks, first and second actuators, and a control circuit. The magnetic disk includes the plurality of tracks. The control circuit writes, in a first track by using the first actuator, second data having a size corresponding to a first number among the first data. In addition, the control circuit writes, in a second track by using the second actuator, third data having a size corresponding to a second number among the first data. Each of the first track and the second track is a track among the plurality of tracks. The first number is a number of writable sectors included in the first track. The second number is a number of writable sectors included in the second track. The third data is data received subsequent to the second data.

A data storage device includes a first actuator and a second actuator rotatable around a common axis. The data storage device further includes a first electrical connector configured to communicate electrical signals to and from the first actuator via a first flexible circuit. The data storage device further includes a second electrical connector separate from but in a stacked arrangement with the first electrical connector. The second electrical connector is configured to communicate electrical signals to and from the second actuator via a second flexible circuit.

Methods and apparatus for allocating logical sectors and bands to store data on interlaced magnetic recording tracks. The systems and methods include formatting a data storage medium to include a plurality of bands, each band of the plurality of bands including a plurality of tracks, the plurality of tracks including a subset of top tracks interlaced with a subset of bottom tracks, and each track of the plurality of tracks including a number of sectors, formatting a first band of the plurality of bands, determining an isolation region of the first band, and formatting a second band of the plurality of bands responsive to determining the isolation region of the first band.

Concurrent standard/high resolution logging of critical performance metrics and functional data for various functional areas including servo system, dataflow, channel, read/write, speed matching, and error recovery is achieved by segregating one or more rows of the tape map array for the purpose of logging only high resolution data. As performance data is logged to the standard resolution tape map by wrap and regional offset down tape, the reserved high resolution row logs data sequentially in the order it was processed on magnetic tape and not by its position on magnetic tape. The high-resolution performance data is concurrently logged with normal-resolution performance data as a supporting view with more detailed tape processing data should the normal-resolution performance data have inconclusive or insufficient content. High-resolution storage is structured for shorter regional logging or per-dataset logging of critical performance metrics and functional data, referred to herein as performance data.

According to one embodiment, a magnetic disk device includes an actuator assembly including an actuator block including a rotatable bearing unit, a plurality of heads movably supported by the actuator assembly, a first sensor provided to the actuator block, and a second sensor provided at a position different from the first sensor.