Implementations disclosed herein provide for detecting an expected or unexpected power loss event on a storage device. Responsive to the detection of the power loss event, a plurality of potentially affected data blocks are identified and/or marked, such as by a processor, to indicate that data stored therein is potentially corrupted.

A computer-implemented method for measuring servo to servo reader spacing in a module, according to one embodiment, includes cause emission of a measurable electro-magnetic signal from two writer elements that are fixed at a same span as a nominal servo reader spacing. The writer elements are positioned in multiple relative positions along a transducer array of a module having servo readers in the transducer array. The strength of the electro-magnetic signal detected by each servo reader is measured at the multiple relative positions. A determination is made, from the measured strengths, whether the servo reader span matches the nominal servo reader spacing.

A magnetic tape includes: a servo band on which servo patterns are repeatedly formed in a longitudinal direction thereof, each of the servo patterns including a first magnetization region formed to be tilted with respect to a width direction of the servo band by a predetermined angle along the width direction of the servo band, and a second magnetization region not parallel to the first magnetization region along the width direction of the servo band, wherein at least one of the first magnetization region or the second magnetization region is formed by decreasing the number of linear patterns from a predetermined plural number of linear patterns and changing a position of the linear pattern to be removed, in accordance with information that is an embedding target so that the information is embedded.

A magnetic disk device includes a magnetic head that writes data on and reads data from the magnetic disk, and a controller circuit. The controller circuit is configured to control a gap between the magnetic head and the magnetic disk, and select one of two or more gap values for the fly height, based on a write location in the magnetic disk of data to be written by the magnetic head.

A magnetic disk device includes a magnetic head that writes data on and reads data from the magnetic disk, and a controller circuit. The controller circuit is configured to control a gap between the magnetic head and the magnetic disk, and select one of two or more gap values for the fly height, based on a write location in the magnetic disk of data to be written by the magnetic head.

According to one embodiment, a magnetic disk device includes a first magnetic disk, a second magnetic disk, a first actuator with a first head which reads/writes data from/to the first magnetic disk, a second actuator with a second head which reads/writes data from/to the second magnetic disk, the second actuator operated independently from the first actuator, a first controller configured to retracts the first actuator at a first time, and a second controller configured to retract the second actuator at a second time which is shifted from the first time by a certain period of time.

According to one embodiment, a magnetic disk device includes a first magnetic disk, a second magnetic disk, a first actuator with a first head which reads/writes data from/to the first magnetic disk, a second actuator with a second head which reads/writes data from/to the second magnetic disk, the second actuator operated independently from the first actuator, a first controller configured to retracts the first actuator at a first time, and a second controller configured to retract the second actuator at a second time which is shifted from the first time by a certain period of time.

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.

First and second tracks are read simultaneously via a first reader mounted in a head-gimbal assembly. The first reader provides a first signal based on detecting a total perpendicular field of the first and second tracks. The first and second tracks are read simultaneously via a second reader mounted in the head-gimbal assembly. The second reader provides a second signal based on detecting a total longitudinal field of the first and second tracks. At least one of a position error and a timing error of at least one of the first and second readers are determined based on user data read via the respective first and second signals.

The invention generally relates to hard disk drives with a disk and a read/write head, and methods for preventing contact between the disk and the read/write head. The hard disk drive includes a z-axis actuator configured to control movement of the read/write head, and to prevent contact between the read/write head and the disk, based on signals from a controller that indicate when the distance between the read/write head and the disk are outside a predetermined range, such as between 0 and 10.0 nm.