Illustrative systems and methods disclosed herein may change or modify a seek during mid-seek for various reasons and may set seek speeds for various seeks to less than the maximum possible seek speed to, for example, facilitate seek target change or modifications mid-seek. For instance, the seek speeds for lower priority commands or commands at risk for deprioritization may be set to speeds less than the maximum possible seek speed.

According to one embodiment, a magnetic disk device includes a first actuator which actuates a magnetic head portion including a magnetic head, a second actuator which adjusts a position of the magnetic head on a magnetic disk in a radial direction of the magnetic disk, and a control portion which determines a second measurement signal amplitude when a second transfer function is measured in accordance with a first gain estimated value of the second actuator and an amplitude of a first measurement signal amplitude to the second actuator applied when a first transfer function is measured, which calculates a second gain estimated value of the second actuator based on the first transfer function and the second transfer function, and which updates the first gain estimated value, using the calculated second gain estimated value.

A data storage device comprising a first actuator configured to actuate a first head over a first disk surface, and a second actuator configured to actuate a second head over a second disk surface. A plurality of access commands are received from a host, and a cost metric is computed for executing a seek to execute each access command of the plurality of access commands, wherein the cost metric is based on an access latency of the seek, a power consumption of the seek, and an estimated combined current draw of the first and second actuators during the seek. The access commands are sorted into an execution order based on the cost metrics computed for the access commands.

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 magnetic disk device includes a disk including a first servo sector including a first preamble, a first servo mark, a first gray code, and first burst data, a head including a write head which writes data to the disk and a read head which reads data from the disk, and a controller which stops write processing, based on a write mask gate different from a first servo gate executing read processing of the first servo sector and a write gate executing the write processing to the disk.

According to one embodiment, a magnetic disk device includes a first actuator which actuates a magnetic head portion including a magnetic head, a second actuator which adjusts a position of the magnetic heal on a magnetic disk in a radial direction of the magnetic disk, and a control portion which determines a second measurement signal amplitude when a second transfer function is measured in accordance with a first gain estimated value of the second actuator and an amplitude of a first measurement signal amplitude to the second actuator applied when a first transfer function is measured, which calculates a second gain estimated value of the second actuator based on the first transfer function and the second transfer function, and which updates the first gain estimated value, using the calculated second gain estimated value.

A data storage device is disclosed comprising a voice coil motor (VCM) having a resonance frequency, a first disk surface comprising a first set of servo sectors written at a frequency less than twice the VCM resonance frequency, and a second disk surface comprising a second set of servo sectors circumferentially offset from the first set of servo sectors and written at a frequency less than twice the VCM resonance frequency. An access of the first disk surface is performed by reading at least one of the first set of servo sectors to generate a first position error signal (PES), reading at least one of the second set of servo sectors to generate a second PES, and controlling the VCM based on the first PES and the second PES to position a first head over the first disk surface while accessing the first disk surface.

A data storage device is disclosed comprising a first actuator configured to actuate a first head over a first disk surface, and a second actuator configure to actuate a second head over a second disk surface. A first seek of the first head over the first disk surface is initiated during a first seek time based on a first seek profile. A second seek of the second head over the second disk surface is initiated during a second seek time based on a second seek profile. When the second seek time at least partially overlaps the first seek time and at least the second seek profile is a de-rated seek profile, the second seek profile is adjusted to avoid an overcurrent condition.

A method includes monitoring an amount of power of a power supply being used by a voice-coil motor (VMC) during a seek operation, detecting that the amount of power has crossed a threshold during the seek operation, and modifying a subsequent seek operation in response to detecting that the amount of power has crossed the threshold.

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.