A tape-shaped magnetic recording medium includes a base, a nonmagnetic layer that is provided on the base and contains a nonmagnetic powder, and a magnetic layer that is provided on the nonmagnetic layer and contains a magnetic powder. In the magnetic recording medium, the magnetic layer has an average thickness of not more than 90 nm, the magnetic powder has an average aspect ratio of from 1.0 to 3.0, a coercive force Hc1 in a perpendicular direction is not more than 3,000 Oe, the coercive force Hc1 in the perpendicular direction and a coercive force Hc2 in a longitudinal direction satisfy the relation of Hc2/Hc1≤0.8, the nonmagnetic layer has an average thickness of not more than 1.1 μm, and the nonmagnetic powder has an average particle volume of not more than 2.0×10.sup.−5 μm.sup.3.

In the probability distribution calculated from TDSage, TDSenv, and TC, the magnetic tape has the probability P.sub.fail of equal to or less than 0.2%, in which the absolute value of ΔSB exceeds 0.3 μm. TDSage is a maximum absolute value of a difference between the servo band interval obtained before a predetermined storage and the servo band interval obtained after the storage, TDSenv is a value calculated by multiplying a difference between a maximum value and a minimum value of the servo band interval respectively obtained under five predetermined environments by ½, TC is a value calculated by multiplying TDStens by 0.5 N, and TDStens is a ratio of a change in the servo band interval to a change in tension calculated from the servo band interval respectively obtained under five predetermined environments by applying a plurality of different tensions in the longitudinal direction of the magnetic tape.

According to one embodiment, a magnetic disk device includes a disk including two first servo sectors and at least a second servo sector, a head, and a controller, wherein the first servo sector includes burst data and a first data pattern written before the circumferential direction of the burst data, the second servo sector includes the burst data, the first data pattern, and a second data pattern written after the circumferential direction of the burst data, a first frequency of the first data pattern is different from a second frequency of the second data pattern, and a first length of the first data pattern is different from a second length of the second data pattern.

According to one embodiment, a magnetic disk device includes a disk including two first servo sectors and at least a second servo sector, a head, and a controller, wherein the first servo sector includes burst data and a first data pattern written before the circumferential direction of the burst data, the second servo sector includes the burst data, the first data pattern, and a second data pattern written after the circumferential direction of the burst data, a first frequency of the first data pattern is different from a second frequency of the second data pattern, and a first length of the first data pattern is different from a second length of the second data pattern.

According to an embodiment, a magnetic disk device includes a magnetic disk including a first storage area and a second storage area different from the first storage area. In the second storage area, both of a first post code that is used to write user data in the first storage area by a first method and a second post code that is used to write user data in the first storage area by a second method are stored in advance. The first method is a method in which one track between two tracks adjacent to each other overlaps a part of the other track between the two tracks. The second method is a method in which two adjacent tracks do not overlap each other.

According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head, and a controller. The magnetic disk has a plurality of tracks. The magnetic head performs reading and writing from and to the magnetic disk. The controller controls write operations to a first region and a second region of the magnetic disk in different manners. The second region is narrower in track pitch than the first region.

A tape-shaped magnetic recording medium includes a substrate; and a magnetic layer that is provided on the substrate and contains a magnetic powder. An average thickness of the magnetic layer is not more than 90 nm, an average aspect ratio of the magnetic powder is not less than 1.0 and not more than 3.0, the coercive force Hc1 in a vertical direction is not more than 3000 Oe, the coercive force Hc1 in the vertical direction and a coercive force Hc2 in a longitudinal direction satisfy a relationship of Hc2/Hc1≤0.8, and a value of σ1.5−σ0.5 is not more than 0.6 N in a tensile test of the magnetic recording medium in the longitudinal direction, where σ0.5 is a load at an elongation rate of 0.5% in the magnetic recording medium and σ1.5 is a load at an elongation rate of 1.5% in the magnetic recording medium.

A servo pattern recording method according to an embodiment of the present technology is a servo pattern recording method of recording a servo pattern on a tape-like magnetic recording medium including a magnetic layer including five or more servo bands, the method including: determining at least three first servo bands in which first servo band identification information constituted by a plurality of bits is to be recorded, and at least two second servo bands in which second servo band identification information constituted by a plurality of bits is to be recorded, the second servo band identification being different from the first servo band identification information; and recording each of the first servo band identification information and the second servo band identification information in the first servo band and the second servo band on the same phase.

According to one embodiment, a magnetic disk device includes a disk including two first servo sectors and at least a second servo sector, a head, and a controller, wherein the first servo sector includes burst data and a first data pattern written before the circumferential direction of the burst data, the second servo sector includes the burst data, the first data pattern, and a second data pattern written after the circumferential direction of the burst data, a first frequency of the first data pattern is different from a second frequency of the second data pattern, and a first length of the first data pattern is different from a second length of the second data pattern.

A hard disk drive includes a magnetic writer and a magnetic recording medium, which includes data tracks with user data sections positioned between servo wedges. The servo wedges each can include multiple servo sectors. The hard disk drive also includes circuitry programmed to cause the magnetic writer to write user data to the multiple servo sectors in multiple servo wedges.