Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Toshiroh Unoki

Minoru Hashimoto

Toru Aida

Mariko Kado

Kenji Kuroki

Shingo Tsuda

Takeshi Shikama

Keishi Takahashi

Makoto Takase

Hiroshi Kawanobe

Naoki Tajima

Selection of disk drive data tracks for the location of reserved area include providing a media disk with data tracks comprising a user data region. A location is assessed on the media disk with a highest frequency of adjacent track interference and far track interference-refresh potential. The location is then configured to be a reserved area where no user data is written. The reserved area has parameters that are read out first before the disk drive enters an operation enabled state for user interface.

System, method and apparatus for selection of reserved area data tracks

Embodiments in accordance with the present invention help a disk drive to effectively cope with a data address mark detection error. In one embodiment, a data sector is provided with plural data address marks and an read/write (RW) channel reads out the data sector using part of those data address marks. Each divisional section of a split sector has two data address marks and the RW channel uses one of the two data address marks. A data address mark to be used is specified by a register. When an error occurs in detecting a data address mark, its position is stored in a register. Based on the error position, an error recovery processing section stores, in the register, a data address mark to be used in a next retry.

Data storage device and error processing method in its read processing

Embodiments of the invention control a recovery procedure effectively in accordance with write conditions. In one embodiment, the data to be written into a sector includes not only user data but also recording condition data, which indicates the temperature prevalent during a write. If a data read is not accurately performed, a recovery procedure is executed. If a data read is accomplished by a retry and the temperature prevalent during a write is lower than predetermined, it is concluded that the employed medium is nondefective. Thus, the read data is rewritten into the same sector without being stored in a spare area. This prevents the spare area from being unnecessarily consumed.

Media drive, processing method for recording data onto a medium, processing method for data read from a medium, and method for controlling a process for reading data from a medium

Embodiments of the present invention relate to retracting a magnetic head of a disk drive device to a retract position in accordance with a fall state, and to suppressing the performance degradation due to erroneous fall determinations as well as occurrence of damage by a head-disk crash. According to one embodiment of the present invention, in a Hard Disk Drive (HDD), a servo controller moves a head slider to a cylinder at the side of a ramp at a predetermined timing that a fall determiner determines that it is falling and an unload controller starts an unload process. This shortens the time between determination by the fall determiner that it is falling to retraction of the head slider to the retract position. Furthermore, it prevents increase of the erroneous determinations by relaxing the fall determination condition for safety. Also, it shortens the time that the head slider returns to the initial position before the seek in case that it is not determined that it is falling.

Disk drive and method of retracting head thereof

Embodiments of the invention provide ways to write data in a load/unload area. In one embodiment, address numbers (ranging from 981 to 1065) whose order of addressing by host equipment is later than that of address numbers (ranging from 1 to 980) as logical block addresses (LBAs) assigned to data sectors in the data area are assigned as LBAs to data sectors whose absolute block addresses (ABAs) range from 1001 to 1100 in the load/unload area. As a result, when the host equipment performs addressing in a magnetic disk drive, the priority order given to the load/unload area becomes low. Accordingly, with the storage capacity being increased, it is possible to prevent the substantial performance from decreasing.

Magnetic disk drive using load/unload area for data storage

When a host apparatus transfers/swaps stored information between user sectors in a storage device for the purpose of defragmentation or the like, the storage device is allowed to perform the data transfer or swap without transmission between the host apparatus and the storage device after the command is received by the storage device; and consistency in stored information identification is maintained between the host apparatus and the storage device even if the operation is interrupted. In one embodiment, information stored in the destination user sector LBA(Y) is copied to the dummy sector LBA(D), its entry is written in the mapping table RDM, information stored in the source user sector LBA(X) is copied to LBA(Y), and then the RDM entry is erased.

Growing community of inventors

Kanagawa, Japan

Toshiroh Unoki