International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Kayo Takahashi

Hirofumi Saitoh

Yuji Yokoe

Kazunari Tsuchimoto

Shohichi Hirashita

Shigemi Suganuma

In a novel method for controlling a disk apparatus having an interface, command storage, and data storage, one or more commands are received from an external apparatus via the interface, and the one or more commands are held in the command storage. A command to be next executed is selected from among the one or more commands and dispatched for execution. It is determined whether an error relating to accessing the data storage has arisen during execution of the selected command. If so, the selected command is restored to the command storage. A subsequent command to be next executed may then be selected. In one described embodiment, an estimated seek time for the selected command is determined, and it is judged that an error has arisen if actual seek time of the selected command exceeds the estimated seek time.

Disk apparatus and control method therefor

A data storage system, a storage medium and a method of controlling a data storage system are described, which allow defects on a storage medium to be handled with a memory region of a reduced size. In one embodiment defective sectors are determined on a magnetic disk and recorded in a defect map as a starting address and a number (length) of consecutive defective sectors to more efficiently record defective sector bursts than in the prior art. Optionally a mixed format defect map may record defective sector bursts as above and single sector defects as an address without a number of consecutive defective sectors.

Data storage system, storage medium and method of controlling a data storage system

Growing community of inventors

Fujisawa, Japan

Kayo Takahashi