According to one embodiment, a first storage area and a second storage area in which a plurality of tracks are set are provided in a radial direction of a magnetic disk. A plurality of post codes corresponding to the second storage area is stored in the first storage area. A controller controls first processing of reading a plurality of post codes from the first storage area and writing the plurality of read post codes in servo area of the second storage area. In the first processing, the controller controls both second processing and third processing in a state where a write head is located on a first track. The second processing is processing of writing a post code among the plurality of read post codes in a servo area. The third processing is processing of writing user data in a data area or reading user data from a data area.

A data storage device can have one or more rotating data media with data tracks that are radially disposed from a central spindle. The data tracks may be logically divided into multiple regions while a write strategy is generated with a region module to set a sequence of different regions for future data writes. Receipt of a data write request to the data storage media from a host can prompt the region module to classify the data write request as a sequential or random write in order to intelligently select a region to satisfy the data write request based on the write strategy to maximize data writing consistency for data associated with the data write request.

In a multi-actuator drive, the effect of moving a first actuator (the so-called “aggressor actuator”) in on a second actuator (the so-called “victim actuator”) is reduced or compensated for. 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. The feedforward signal is configured to compensate for disturbances to the victim microactuator caused by VCM commands provided to the aggressor actuator. The feedforward signal is based on a transfer function that models commands added to the victim microactuator, which is coupled to the head of the victim actuator, as a function of the aggressor VCM control signal applied to the aggressor actuator.

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.

Systems and methods are disclosed for calibrating actuators in a multi-stage servo system. In certain embodiments, a method may comprise performing a calibration process on a multi-stage actuated servo system, including simultaneously injecting voltage injections into multiple microactuators of the servo system, measuring a resulting position error signal (PES), and determining gain settings for each of the multiple microactuators based on the PES. Multiple microactuators can therefore be calibrated during a single-injection calibration operation.

A data storage device is disclosed comprising at least one head configured to access a magnetic tape. A plurality of access commands are stored in a command queue, and a wear value is generated for each access command in the command queue, wherein the wear value represents a level of wear on the head or magnetic tape associated with executing the access command. An execution order for the access commands is generated based on the wear values, and at least one of the access commands is executed based on the execution order.

In a multi-actuator drive, the effect of moving a first actuator (the so-called “aggressor actuator”) in on a second actuator (the so-called “victim actuator”) is reduced or compensated for. A victim feedforward signal for a particular head of the victim actuator 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. The feedforward signal is configured to compensate for disturbances to the victim microactuator caused by VCM commands provided to the aggressor actuator. The feedforward signal is based on a transfer function that models commands added to the victim microactuator, which is coupled to the particular head of the victim actuator, as a function of the aggressor VCM control signal applied to the aggressor actuator.

In a multi-actuator drive, the effect of moving a first actuator (the so-called “aggressor actuator”) in on a second actuator (the so-called “victim actuator”) is reduced or compensated for. A victim feedforward signal for a particular head of the victim actuator 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. The feedforward signal is configured to compensate for disturbances to the victim microactuator caused by VCM commands provided to the aggressor actuator. The feedforward signal is based on a transfer function that models commands added to the victim microactuator, which is coupled to the particular head of the victim actuator, as a function of the aggressor VCM control signal applied to the aggressor actuator.

A data storage device is disclosed comprising a storage medium, an input configured to receive a supply voltage from a voltage source, and control circuitry powered by the supply voltage. The control circuitry is configured to adjust a load of the data storage device, detect a load voltage at the adjusted load, detect a load current at the adjusted load, process the detected load voltage and the detected load current to detect a current limit of the voltage source, and configure the data storage device in response to the detected current limit of the voltage source.

According to one embodiment, a control device to be used for a magnetic disk device includes a power source control section and a control section. The power source control section configured to change an output voltage value of a voltage supplied to the control device from a power source on the basis of a voltage control parameter. The control section configured to, when a magnetic head makes access to a zone set on a magnetic disk, set a voltage control parameter provided in such a manner as to be correspondent to the zone to the power source control section.