KR100440791B1 - Method for dynamically managing a defect, specially in connection with improving the reliability of a drive by performing defect management under user environment - Google Patents

Abstract

PURPOSE: A method for dynamically managing a defect is provided to detect a defect generated under user environment as well as a fabrication process through a latent defect scan routine, thereby improving drive reliability while preventing a loss of user data. CONSTITUTION: A system detects a defect by performing a defect scan for an entire hard disk when fabricating the hard disk(40). The system records defect information on the detected defect in a static area of a defect list(42). The system carries out a defect scan for entire areas of a hard disk surface while a hard disk drive is operated, and detects a defect(44). The system records the detected defect information in a dynamic area of the defect list(46). The system merges the static area and the dynamic area together(48).

Description

DYNAMIC Defect Management

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the management of defect sectors (hereinafter referred to as defects) of a hard disk drive, and more particularly, to a dynamic defect management method for dynamically managing defects generated during the use of a drive.

A hard disk drive, which is a secondary storage device of a computer system, uses basic units such as track, head, and sector to record and read data on a disk surface. In the manufacturing process, there is an area on the disc surface where data cannot be recorded normally due to a defect in the media (i.e., a disc) or other reasons, which is generally called DEFECT. If there are defects on the disk surface, use the technique called defect management to prevent the area from being accessed under the user environment. Hereinafter, the defect management technique widely used by the hard disk drive manufacturers will be described. As a first technique, a spare sector is provided for each track to reallocate the spare sector when a defect occurs. As a second technique, there is a technique of reallocating a defect sector by allocating a predetermined area or cylinder as a spare. As a third technique, there is a technique of slipping to the next sector (SLIP) when a defect occurs, and some manufacturers use a combination of the above techniques.

When the drive is assembled in the manufacturing process, the above-described defect management techniques commonly detect defects through a media defect scanning process, and list the information of the detected defects in a list to implement the defect management technique in the firmware (FIRMWARE). Defect processing through In general, during the media defect scanning process, the defect condition is increased by increasing the probability of occurrence of the defect, and thus the probability of occurrence of additional defects that may occur in the user environment is reduced by detecting the defect. However, since each of the above-described defect management techniques is performed only once in the manufacturing process, there is no treatment technique for additional defects occurring in the user environment. To compensate for this problem, auto-reverse sign (AUTO-REASSIGN) has been added.However, this is mainly to prevent the write fault while using the write cache. It is not a technique for scanning and then reallocating the defect list to dynamically manage it. Therefore, in case of using the conventional defect management technique, the reliability of the drive may be degraded by data loss due to the defect generated in the user environment, and there is a problem that a lot of expense is required even in the A / S (AFTER / SERVICE) dimension. .

Accordingly, an object of the present invention is to provide a dynamic defect management method capable of improving the reliability of a drive by performing defect management under not only a manufacturing process of a hard disk drive but also under a user environment.

In order to achieve the above object, the present invention provides a hard disk drive having a defect list in which information on a defect detected during a manufacturing process is recorded.

A latent descan process that detects a defect by performing a defect scan on the entire disk surface in a user environment;

Defect information merging is performed by recording the defect information detected in the latent defect scanning process into the defect list and merging with the defect information detected during the manufacturing process.

1 is a block diagram of a typical hard disk drive.

Figure 2 is a defect management flow chart for explaining the defect processing in the manufacturing process and the defect processing in the user environment for the dynamic defect management in accordance with an embodiment of the present invention.

FIG. 3 is a diagram illustrating a defect list recording on a maintenance area in which a defect list created according to the defect management flow of FIG. 2 is recorded; FIG.

Hereinafter, a dynamic defect management method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a general hard disk drive. Referring to FIG. 1, the microprocessor 10 may include a programmable read memory 12 that stores a predetermined control program and an estimator algorithm of the microprocessor 10, and a static RAM. Random Access Memory (hereinafter referred to as SRAM) 14 to control the overall operation of the drive. The head 16 is attached to one end of the actuator to perform horizontal movement on the disk 18, which is a recording medium, and to record and reproduce data on and from the disk 18 surface. The voice coil motor (VCM) 20 located at the other end of the actuator with the head 16 attached to one end is horizontally driven on the disk 18 in correspondence with the applied current level and direction. The spindle motor 22 rotates the disk 18 mounted on the drive shaft in accordance with the control signal input from the motor driver 40. The VCM driver 36 is connected to the VCM 20 to control the driving of the VCM 20. A digital-to-analog converter (DAC) 28 is connected to the microprocessor 10 and the VCM driver 26 to receive a digital control input signal U (k) from the microprocessor 10 and to output an analog signal. Is converted to the VCM driver 26 and output.

The motor driver 24 is connected to the spindle motor 22 and the microprocessor 10 and controls the driving of the spindle motor 22 under the control of the microprocessor 10. The pre-amplifier 30 is connected to the head 16 to amplify and output the reproduced signal, and outputs an input signal to the head 16 to be recorded. The read / write channel circuit 32 is connected to the microprocessor 10, the preamplifier 30, and the interface controller 34, and receives recording data from the interface controller 34 under the control of the microprocessor 10. This is encoded and output to the preamplifier 30. The read / write channel circuit 32 digitally converts the analog reproduction signal input from the preamplifier 30 and outputs the encoded read data as encoded read data (ERD). An analog-to-digital converter (ADC) 36 is connected to the read / write channel circuit 32 to receive an analog servo regeneration signal, and digitally converts it to PES and outputs it to the microprocessor 10. A gate array 38 is connected to the read / write channel circuit 32 to receive an ERD signal and detects and outputs servo information such as gray codes in the servo region of the disk 18 from the ERD signal. do. The interface control unit 34 transmits and receives data between the external data input device (for example, a host computer) and the disk 18.

FIG. 2 is a flowchart illustrating a defect management process for simultaneously describing a defect processing process in a manufacturing process and a defect processing process in a user environment for dynamic defect management according to an embodiment of the present invention, and FIG. 3 is a defect of FIG. An example of a defect list recording on the maintenance area in which the defect list created according to the management flow is recorded is shown.

Hereinafter, a dynamic defect management method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

First of all, the implementation of the dynamic defect management method according to an embodiment of the present invention is a process of changing the defect management method of the defect list and hiding process (HIDDEN). That is, the defect list is divided into a static area in which the defect information detected in the manufacturing process is recorded, and a dynamic area updated in the user environment, and a scan table required for latent defect scanning in the user environment. The log table must be added. In FIG. 2, steps 40 and 42 are performed during the manufacturing process, respectively, and the microprocessor 10 scans the defects of the entire disk 18 through 40 steps. In operation 42, the microprocessor 10 records the detected defect information in the static defect region on the defect list. The defect list is generally recorded in the maintenance area located at the outermost circumference of the disk 18 surface. If predetermined sectors are detected as defects in the defect scanning process, the microprocessor 10 records the corresponding defect information in the static defect region A of the defect list 50 as shown in FIG. Hereinafter, a process of recording the decode information detected by the latent defect scan routine and the latent defect scan routine performed in the user environment in the defect list 50 through the 46 steps will be described.

First, the latent defect scanning routine is defined as a process of scanning the defect of the disk 18 surface during the drive operation. The latent defect scanning routine is executed when there is no command input from the outside (ie, the host computer) for a predetermined time. If there is a command input from the outside during the execution of the latent defect scanning, the current scan position is recorded and the corresponding command input After the operation is performed, the Defect Scan operation is performed again. In detail, first, if there is no command input from the outside for a predetermined time, the microprocessor 10 starts the defect scanning in the direction of increasing the cylinder, head, and sector numbers starting from cylinder number 0 and head number 0. Read / write retries, error correction, off-track, etc. can be set to add stress to the de-scan. The error occurred during the defect scanning process is logged into the dynamic defect log list or the buffer, and the log is determined when the scan is completed for a predetermined block or more. This criterion can be determined by the number of retry attempts, error correction on / off, and the like. In order to eliminate the possibility of errors due to write errors, the write criteria are read again, and then the read data is read after the error correction is turned off. If a particular sector is determined to be a defect through this process, the microprocessor 10 records the corresponding defect information in the dynamic defect region B of the defect list 50 as shown in FIG. Thereafter, the microprocessor 10 merges the dynamic defect region and the static defect region as shown in (III) of FIG. 3 through step 48 and returns to step 44. If there is a command input from the outside during steps 44 to 48, the microprocessor 10 records the current scan position and then completes the operation according to the user's command input and starts scanning again. Such a latent defect scan routine may be performed for the entire area of the disk 18 surface, and the next latent defect scan routine may be performed at a predetermined time interval.

As described above, the present invention has the advantage of improving the reliability of the drive and preventing the loss of user data by detecting the defect generated under the user environment as well as the manufacturing process.

Claims (2)

In the defect management method of a hard disk drive having a defect list divided into a static area and a dynamic area, A first defect scanning process of detecting defects by performing a defect scanning on the entire hard disk during the manufacturing process of the hard disk; A first storage process of recording the defect information on the defect detected in the first defect scan process in the static area of the defect list; A latent descanning process of detecting a defect by performing a defect scan of the entire area of the hard disk surface while the hard disk drive is operating under a user environment; A second storing step of recording the defect information detected in the latent defect scanning process into the dynamic area of the defect list; And a merging process of merging the static area of the defect list and the dynamic area of the defect list. The method of claim 1, wherein the latent descan process is performed when there is no command input for a predetermined time from the outside of the drive, and when the command input is received from the outside during execution, the latent descanning process is performed again after completion of operation according to the corresponding command input. Defect management method.

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