International Business Machines Corporation

Haruo Andoh

Keiji Kobayashi

Kazunari Tsuchimoto

Hiroaki Suzuki

Hideo Asano

Isao Yoneda

Takashi Nakamura

Yuji Yokoe

Shinji Ueno

Tatsuya Endo

Atsushi Tobari

Kazuyuki Kobayashi

Shuji Yamada

Satoshi Nishino

Yasuhiro Iihara

Takahi Kuroda

Toru Aida

Tsuguaki Kowa

A method and system are disclosed to provide a defect map structure that can increase the throughput of a recording apparatus when the recording apparatus accesses a data recording medium. A defect register method according to the present invention includes the steps of detecting initial defective sectors, generating a primary defect map (PDM) where each absolute block address of initial defective sectors (D.ABA) is individually registered, discriminating a series of defective sectors consisting of a plurality of initial defective sectors with continuous D.ABA, which exist in the same track (tracks having the same cylinder identification number CYL and head identification number HED) from the individual resister PDM, and generating a PDM, where this series of defective sectors is registered in a batch, by registering a first absolute block address of the series of defective sectors (D.ABA.ST), and defective sector length (number of defective sectors D.LE) of the series of defective sectors.

Method for registering, in a defect map, addresses of defective sectors of a data recording medium

An Error Recover Procedure (ERP) is disclosed which, during execution of the ERP, while self-diagnosing the cause of error, dynamically changes the error recovery steps of the ERP. An appropriate ERP is selected and executed according to the detected error status.

Method and device for error recovery

A method and apparatus for relocating the data in defect sectors having occurred in the storage medium of an information recording and reproducing apparatus is described. If a defect occurs in a sector of a user area, the data of it is relocated to a temporary storage area. The logical block addresses (LBA's) for a group of sectors including an alternate sector are sequentially reassigned by skipping the defective sector and including the alternate sector. Data in the group of sectors are read out from the rear part of the user area according to current LBAs, and written according to new LBAs. Since the addresses of new LBAs are smaller than those of current LBAs by the number of defect sectors, the original data is not destroyed in the writing.

Method for managing defect sectors of information storage medium, and apparatus for use with the method

The present invention provides a disk drive, a load/unload unit, and a control method thereof which are capable of reliably unloading a head slider from a disk when power is turned off and enhancing reliability. A disk drive is equipped with a VCM spindle driver for rotating a disk, a magnetic head, an actuator mechanism for moving over the surface of the magnetic disk or to an evacuating position a head slider having the magnetic head, a ramp block, and a CPU/HDC (control means) for performing control of load and unload operations, speed control of the actuator mechanism, and control of an operation of reading or writing data from or to the disk. The CPU/HDC receives a specific command issued from the host immediately before power is turned off, and executes this command, then executes unload control, and notifies the host of command completion after the unload control has been completed.

Disk drive, load/unload unit, and control method thereof

Even in the case of a full hang state where a command to reset software is entirely ineffective, memory dump can be stored even if there is no in-circuit emulator. An HDD itself monitors a command execution time, that is, the time between reception of a command from a host computer and completion of the process of the command. If the HDD judges that it has taken an abnormally long time, a memory dump will be automatically stored on a reserved area on a disk. The memory dump can be read out from the disk at any time so that an analysis can be made.

Information storing method, information storing unit, and disk drive

To decrease the number of read errors of a storage device due to bus noise when data is transferred between a host apparatus and the storage device. When a read error due to bus noise is detected, transfer of data to a host apparatus is temporarily stopped when executing rereading to eliminate bus noise which is a cause of the read error. In a preferred embodiment bus noise errors are distinguished by looking at the frequency of errors and the retry count for the previous error. The error is detected as a bus noise error if the frequency is above a threshold and the retry count is below a threshold. Data transfer can be restarted when a buffer becomes full or when the reading of the data is successfully completed.

Data read apparatus and data read method

An error recovery procedure (ERP) in a storage device such as a rotating magnetic hard disk drive is executed to the last step regardless of the established time-out period for an instruction, thereby more reliably recovering from errors. In accordance with one embodiment of the invention, when a disk drive receives a reset instruction from a host during the execution of an ERP, it executes the ERP until the error is recovered, or to the last step without interrupting the ERP. Further, in accordance with another embodiment of the invention, when a disk drive receives a reset instruction during the execution of an ERP, it stops execution of the ERP and holds the number K of the step which was completed immediately before stopping, and when receiving a retry instruction after that, sequentially executes the ERP from the K+1-th error recovery step.

Method for executing an error recovery procedure

A disk drive has an error recovery procedure with a plurality of ERP steps. An unused capacity of an alternate area on a disk for reassigning data is determined. While executing the error recovery procedure, an execution condition for reassigning data is changed based unused capacity of the alternate area. Data is reassigned to the alternate area in response to the execution condition. This prevents the early loss of the alternate area.

Growing community of inventors

Zama, Japan

Haruo Andoh