According to one embodiment, a magnetic disk device includes a disk having a first region in which a plurality of tracks is written and a second region that is positioned with a gap in a first direction of the radial direction of the first region, and in which a plurality of tracks is overwritten in the first direction, a head, and a controller that offsets part of a plurality of tracks which is overwritten in the second region in a second direction opposite the first direction to perform rewriting.

A computer-implemented method for indexing a tape for unmounting from a tape drive. The computer-implemented method includes: receiving a request to unmount the tape from the tape drive, wherein the tape includes an index partition and a data partition, determining that an update to the tape is not reflected in any data index written in the data partition, appending a new data index at the end of the last written data file in the data partition, wherein the new data index includes information associated with the update to the tape, unthreading the tape from the tape drive, wherein unthreading the tape from the tape drive is performed at low tension writing a metadata index to an ancillary storage device, wherein the metadata index includes information associated with the update to the tape.

Methods and systems for managing data storage strategies for continuous video segment recordings on a video recording device are disclosed. The data storage strategies include the detection of various trigger events and ending events detected from the video recordings or measurements detected from sensor devices that are included in the video recording device.

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.

According to one embodiment, a magnetic disk device includes: a disk; a head including a main magnetic pole, a write shield that faces the main magnetic pole in a first direction and is separated from the main magnetic pole by a gap, a first assist element that is disposed in the gap and a second assist element that is disposed in the gap and is positioned relative to the first assist element in a second direction intersecting the first direction; and a controller configured to: cause a first assist energy from the first assist element to be applied to the disk and affect a coercive force of the disk; and cause a second assist energy from the second assist element to be applied to the disk and affect a coercive force of the disk, wherein the first assist energy is different from the second assist energy.

According to one embodiment, a magnetic disk device includes a disk, a head which writes data to the disk and reads data from the disk, and a controller which increases a first recording density of data to be written to a first sector having a first overwrite in the first sector and reduces a second recording density of data to be written to a second sector having a second overwrite different from the first overwrite, on a first track of the disk.

Technologies are provided for partially updating shingled magnetic recording (SMR) zones in SMR storage devices. An SMR storage device can receive and process a command to update a write pointer for an SMR zone to point to an arbitrary write position within the SMR zone. A partial SMR zone update command can be received and processed to modify part of the data stored in the SMR zone. A write position within the SMR zone where data to be modified is stored can be identified. Data stored in the SMR zone following the identified write position can be read to a temporary location and modified. A write pointer for the SMR zone can be updated to point to the identified write position. The modified data can then be written to the SMR zone, starting at the write position identified by the write pointer, or to another SMR zone of the storage device.

A recording control apparatus includes a video data acquisition unit configured to acquire video data obtained by shooting an area around a vehicle, an event detection unit configured to detect an occurrence of a predetermined event in the vehicle, a changing-point determination unit configured to determine whether or not the vehicle has passed a changing point on a traveling road based on a current position information of the vehicle, and a recording control unit configured to, when the event detection unit detects the occurrence of the event, record the video data including a first period as an event recording file in a recording unit, the first period being from a passing time point of the changing point to a detecting time point of the event, the changing point being a point that the vehicle has passed at least a first time earlier than the detecting time point of the event.

According to one embodiment, a magnetic disk device includes: a disk; a head including a main magnetic pole, a write shield that faces the main magnetic pole in a first direction and is separated from the main magnetic pole by a gap, a first assist element that is disposed in the gap and a second assist element that is disposed in the gap and is positioned relative to the first assist element in a second direction intersecting the first direction; and a controller configured to: cause a first assist energy from the first assist element to be applied to the disk and affect a coercive force of the disk; and cause a second assist energy from the second assist element to be applied to the disk and affect a coercive force of the disk, wherein the first assist energy is different from the second assist energy.

A recording device includes: a recording unit that records plural objects including data and metadata related to the data on a portable recording medium, and executes a process of recording first set data, which is a set of the metadata included in the object, at every predetermined timing after recording at least one of the objects, wherein each piece of the first set data is a set of the metadata included in the object recorded after recording of immediately preceding recorded first set data.