A tape cartridge for use in one or more tape drives of a tape library includes a cartridge housing and a magnetic tape. The magnetic tape is retained within the cartridge housing. The magnetic tape includes a first tape section that is pre-recorded with calibrated data for evaluating data durability on the magnetic tape. The magnetic tape is usable within the tape library to measure a health of the one or more tape drives and/or confirm a suitability of an operating environment within the tape library in terms of at least one of temperature and humidity. The calibrated data in the first tape section can be further configured for evaluating total transverse dimensional stability on the magnetic tape. The first tape section can include predetermined error patterns to assist in evaluating the data durability on the magnetic tape and/or periodic tape scrubbing operations to enhance data durability on the magnetic tape.

A victim feedforward signal is added to a microactuator control signal of the victim actuator in response to a voice-coil motor (VCM) control signal that is applied to the aggressor actuator, where the victim feedforward signal is configured to compensate for disturbances to a victim head caused by assertion of the aggressor VCM control signal. Each aggressor VCM control signal is asserted at a specific time by the aggressor actuator, for example in response to the aggressor head passing over a first servo wedge. A feedforward signal that compensates for the effect of the aggressor VCM control signal is then determined based on the aggressor VCM control signal, stored, and asserted via the victim microactuator at a predetermined time relative to when the aggressor VCM control signal is asserted.

A two-dimensional magnetic recording (TDMR) disk drive has a gas-bearing slider that includes first and second sensors with a first cross-track spacing electrically coupled to a first magnetic shield, and third and fourth sensors with a different cross-track spacing electrically coupled to a second magnetic shield. The different spacings results in the first and third sensors and the second and fourth sensors having a cross-track spacing to accommodate for the effect of head skew. Each sensor is connected to an associated amplifier by a suspension trace and a common trace connected to its associated shield. Switching circuitry selects either the first and third amplifiers or the second and fourth amplifiers as the active pair depending on the radial location where the data is to be read. Thus the appropriate pair of sensors are aligned with the data tracks despite the presence of high head skew.

Various illustrative aspects are directed to a data storage device comprising one or more disks; an actuator arm assembly comprising one or more actuator arms, and configured to position the one or more actuator arms over disk surfaces of the one or more disks; one or more fine actuators, disposed on the one or more actuator arms; and one or more processing devices. The one or more processing devices are configured to: output a driver current to the one or more fine actuators, wherein the one or more processing devices are configured to rate limit a rise of the driver current over time during an activation of the driver current to within a selected rate limit of current rise over time.

A tolerance ring includes a base formed of a strip-like member approximately wound around into a ring shape, and a plurality of projections provided along a winding direction of the base so as to protrude in a radial direction from an outer peripheral surface of the base, wherein each of the projections has edges serving as a boundary with the base and at least one of the edges in a width direction orthogonal to the winding direction has a shape intersecting the winding direction.

In illustrative aspects, a system comprises an actuator; a control object, controlled by the actuator; and one or more processing devices. The one or more processing devices are configured to perform positioning control of the control object via the actuator, wherein performing the positioning control comprises: generating a feedforward polydyne positioning control input; and outputting the feedforward polydyne positioning control input to the actuator.

A Data Storage Device (DSD) includes at least one disk surface and a plurality of actuators for accessing data stored on the at least one disk surface. A workload is determined for each actuator of the plurality of actuators, and a logical to physical mapping is modified based on at least one workload. The logical to physical mapping associates logical addresses of data with physical locations for storing the data on the at least one disk surface.

A flexure assembly is described. The flexure assembly includes a gimbal portion on configured to receive a slider. The gimbal portion includes a first surface and a second surface which is opposite to the first surface. The slider is mounted on the second surface. The flexure assembly also includes a pair of microactuator elements. The flexure assembly also includes a tongue of the gimbal portion on which the slider is mounted. The tongue includes a dimple point which represents the center of the tongue. The flexure assembly also includes a pair of first supporting portions and a pair of second supporting portions of the gimbal portion. A pair of end portions are individually secured to the tongue and the first supporting portions and the pair of second supporting portions. The flexure assembly also includes a conductive circuit portion unsupported between a first stationary part and the pair of end portions.

According to one embodiment, a method for manufacturing a magnetic disk device includes: moving a magnetic head such that a read head is located on a first learning position among a plurality of learning positions set in a radial direction of a magnetic disk; and learning RRO correction information related to the first learning position using the read head. The method further includes: moving the magnetic head such that the read head is located on a second learning position among the plurality of learning positions; and executing writing of the RRO correction information related to the first learning position using the write head in parallel while learning RRO correction information related to the second learning position using the read head when the read head is located on the second learning position.

A method for writing repeatable run-out data, representing a recurring contribution to position error, to a rotating constant-density magnetic storage medium, includes repeating, for each respective track at a respective radius of the constant-density magnetic storage medium, (1) determining a respective track pattern frequency based on track location and desired data density, (2) locating a position in a respective servo wedge on the respective track based on servo sync mark detection, (3) writing the repeatable run-out data to the respective servo wedge at a time delay, from the location of the position in the respective servo wedge, that is inversely proportional to the respective radius, to achieve a predetermined offset, and (4) repeating the determining, the locating and the writing for each servo wedge on the respective track of the constant-density magnetic storage medium.