KR100699877B1 - Method for preserving data of the defect sector and disc drive using the same - Google Patents

Abstract

A data preservation method of a defect sector in a data storage system and a disk drive using the method are provided to record data to be recorded in the defect sector, in both an alternative sector and a mirror alternative sector which pairs with the alternative sector, if a defect is generated, thereby preserving the data without losing the data by using the mirror alternative sector even though a defect is generated from the alternative sector later. If a defect sector is generated, an alternative sector corresponding to the defect sector is allocated in a spare area, and data to be written on the defect sector is written on the alternative sector(S310-S350). The data to be written on the defect sector is written on a mirror alternative sector which pairs with the alternative sector in the spare area(S360). Position information of the mirror alternative sector is determined by regular access rules from alternative sector information.

Description

Method for preserving data of the defect sector and disc drive using the same}

1 is a plan view of a head disk assembly of a disk drive to which the present invention is applied.

2 is an electrical circuit diagram of a disk drive to which a method for preserving data of a defect sector in a data storage system according to the present invention is applied.

3 is a flowchart of a data write process according to a method for preserving data of a defect sector in a data storage system according to the present invention.

4 is a flowchart of a data read process according to a method of preserving data of a defect sector in a data storage system according to the present invention.

5 (a) to 5 (f) are sector configuration diagrams of a disc for explaining a data storage method of a defect sector in a data storage system according to the present invention.

The present invention relates to a data processing method and apparatus for a data storage system, and to a method and apparatus for reducing the possibility of data loss of a defect sector in a disk drive.

In general, a hard disk drive, which is one of data storage devices, contributes to computer system operation by reproducing data recorded on a disk by a magnetic head or recording user data on the disk. As such hard disk drives are gradually increasing in capacity, density, and miniaturization, bit per inch (BPI), the recording density in the direction of disk rotation, and track per inch (TPI), the recording density in the radial direction, are increasing. Is required.

In the hard disk drive, the disk is rotated by the constant rotation of the spindle motor, and the servo information of the disk is read and read at the same time interval by the transducer (also called a head). The position of the data sector is determined to perform data write and read operations.

In the manufacturing process of the hard disk drive, no defects can be found, but additional new defects can be found in the user's environment. One technique is sector reassignment.

The sector reallocation technique according to the prior art has two methods as follows.

The first method sets the last two cylinders of each zone of the disk divided into a plurality of zones as spare cylinders, and the sector where the defect is found when a defect is found in each zone of the disk. This is a method of reallocating the defect sector to the spare cylinder of the corresponding zone instead.

The second method is to set two sectors as spare sectors on every track of the disc and replace the sectors where the defects are found with the sectors at the spare sector locations of the tracks containing the sectors where the defects were found. A method of reallocating sectors.

In the case where defects are generated in the replacement sector reassigned by the sector reassignment processing method as described above, data may be lost.

The technical problem to be solved by the present invention is to prevent data loss even if a defect is generated in one alternative sector by writing data to be written to the defect sector in a plurality of sectors of the spare area when the defect is generated in order to solve the above problem. The present invention provides a method of preserving data of a defect sector in a data storage system and a disk drive using the same.

In order to achieve the above technical problem, the data storage method of the defect sector in the data storage system according to the first embodiment of the present invention is the data storage method of the defect sector in the data storage system. (a) when a defect sector is generated, allocating a replacement sector corresponding to the defect sector in a spare area, and writing data to be written to the defect sector to the replacement sector; And (b) writing data to be written to the defect sector in the mirror replacement sector paired with the replacement sector in the spare area.

In order to achieve the above technical problem, in the data processing method of the data storage system according to the second embodiment of the present invention, (a) when a defect sector is generated, a replacement sector corresponding to the defect sector in the spare area; Writing data to be written to the defect sector in sectors paired with the replacement sector according to a certain access rule; And (b) reading data stored in a sector paired with the replacement sector when an error occurs while reading data stored in the replacement sector.

According to another aspect of the present invention, there is provided a disk drive, comprising: a disk for storing information including a predetermined spare area for reallocating a defect sector; When a defect is generated during data processing, a control process of allocating a replacement sector corresponding to the defect sector in the spare area and writing data to be written to the defect sector to the replacement sector, and the replacement sector in the spare area. A control process of designating a mirror replacement sector to be paired with and writing data to be written to the defect sector to the mirror replacement sector, and if an error occurs in the process of reading data stored in the replacement sector, pairing with the replacement sector. A controller for executing a control process of searching for a mirror replacement sector to form a data; And a write / read circuit for performing data processing for writing data to or reading data from the disk in accordance with the control process.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hard disk drives consist of a combination of electrical circuits and a head disk assembly (HDA) consisting of mechanical components.

1 shows a configuration of a head disk assembly (HDA) 10 of a hard disk drive to which the present invention is applied.

The head disk assembly 10 includes at least one magnetic disk 12 that is rotated by the spindle motor 14. The disk drive 10 also includes a transducer 16 located adjacent to the surface of the disk 12.

The transducer 16 can read or write information on the rotating disk 12 by sensing and magnetizing the magnetic field of each disk 12. Typically transducer 16 is coupled to the surface of each disk 12. Although illustrated and described as a single transducer 16, it should be understood that this consists of a write transducer for magnetizing the disc 12 and a separate read transducer for sensing the magnetic field of the disc 12. Read transducers are constructed from Magneto-Resistive (MR) devices. The transducer 16 is also commonly referred to as a head.

The transducer 16 can be integrated into the slider 20. The slider 20 is structured to create an air bearing between the transducer 16 and the surface of the disk 12. The slider 20 is coupled to the head gimbal assembly 22. The head gimbal assembly 22 is attached to an actuator arm 24 having a voice coil 26. The voice coil 26 is located adjacent to the magnetic assembly 28 that specifies the voice coil motor 30 (VCM). The current supplied to the voice coil 26 generates a torque for rotating the actuator arm 24 relative to the bearing assembly 32. Rotation of the actuator arm 24 will move the transducer 16 across the disk 12 surface.

The information is typically stored in an annular track of the disc 12. Each track 34 generally includes a plurality of sectors. Each sector includes a data field and an identification field. The identification field is composed of a gray code identifying a sector and a track (cylinder). The transducer 16 is moved across the surface of the disc 12 to read or write information on other tracks.

The disk 12 is also divided into a plurality of zones, each of which is assigned a spare cylinder for replacing a defect sector. As an example, the spare cylinder can be designed to be assigned to two tracks for each zone. In the present invention, the spare cylinder area is divided into a cylinder area for allocating a replacement sector and a cylinder area for allocating a mirror replacement sector paired with the replacement sector.

2 shows an electrical system 40 capable of controlling a hard disk drive. The electrical system 40 includes a controller 42 coupled to the converter 16 by a lead / right (R / W) channel circuit 44 and a pre-amp circuit 46.

The controller 42 may be a digital signal processor (DSP), a microprocessor, a microcontroller, or the like. The controller 42 reads and writes the read / write channel circuits to read information from or write information to the disk 12 according to a command received from the host device through the host interface circuit 54. 44).

The controller 42 is also coupled to a VCM drive circuit 48 that supplies a drive current to the voice coil 26. The controller 42 supplies a control signal to the VCM driver 48 to control the excitation of the voice coil motor and the movement of the transducer 16.

The ROM 50 stores firmware and various control data for controlling the disk drive. Of course, programs for performing a flowchart of a method for preserving data of a defect sector in the data storage system of FIG. 3 and FIG. 4 are also stored.

When power is supplied to the disk drive, the RAM 52 loads various parameter information and replacement sector reassignment lists, which are disk drive information read from a maintenance cylinder location of the disk 12.

First, the operation of a general disk drive will be described.

In the data read mode, the disc drive amplifies the electrical signal sensed by the transducer 16 from the disc 12 in the preamplifier 45 to facilitate signal processing. The read / write channel circuit 44 then encodes the signal read out from the disk 12 into digital signals in accordance with sector pulses generated by the controller 42, converts the signal into stream data, and converts the host interface circuit 54 into a stream signal. To the host device.

Next, in the write mode, the disk drive receives data from the host device through the host interface circuit 54 and temporarily stores the data in an internal buffer (not shown) of the host interface circuit 54 and then stores the data in the buffer. Recorded data amplified by the preamplifier 45 at the time of sector pulse generation after the stored data are sequentially output and converted into a binary data stream suitable for the recording channel of the disc 12 by the read / write channel circuit 44. Current is written to disk 12 via converter 16.

According to the present invention, when a defect is generated in the process of performing data processing in the read / write channel circuit 44, the controller 42 rewrites the replacement sector corresponding to the defect sector in the spare area of the disk 12. A control process that allocates and writes data to be written to the defect sector in a reassigned replacement sector, replacing another sector (hereinafter referred to as a mirror) paired with the corresponding replacement sector in accordance with certain access rules in the spare area of the disk 12. Control process that writes data to be written to the corresponding defect sector in the mirror replacement sector, and mirror replacement sector paired with the corresponding replacement sector when a defect occurs in the process of reading data stored in the replacement sector. To execute the control process of reading the data.

Next, a method of preserving data of a defect sector in a data storage system according to the present invention will be described with reference to the flowcharts of FIGS. 3 and 4 with reference to the configuration of the disk drive of FIG. 2.

First, the WRITE process according to the data preservation method of the defect sector in the data storage system according to the present invention will be described with reference to FIG. 3.

The controller 42 determines whether the controller enters the write mode according to the data write command received from the host device (not shown) (S310).

When entering the write mode, the controller 42 executes the data write mode after moving the converter 16 to the target track to be recorded on the disc 12 (S320).

In operation S330, it is determined whether a defect sector is generated in the process of writing data. Defect sectors in the data recording process are generated when, for example, Servo signals are not normally detected.

As a result of the determination in step 330 (S330), as shown in FIG. 5 (a), when the defect sector D2 is generated, the controller 42 replaces the replacement sector corresponding to the defect sector D2 in the spare area of the disc 12. (S129) Reallocates and adds to the replacement sector reassignment list (S340).

The controller 42 controls to move the converter 16 to the replacement sector position, and then, as shown in Fig. 5B, the data to be recorded in the defected sector D2 is stored in the replacement sector S129. Control to record (S350).

Next, as shown in FIG. 5C, the controller 42 controls to record data to be recorded in the sector where the defect has been generated in another sector (mirror replacement sector) paired with the corresponding replacement sector (S360). .

The position of the mirror replacement sector paired with the above defect sector is determined in the spare area according to a certain access rule. The present invention provides two examples of determining the position of the mirror replacement sector.

case1) Position information of mirror replacement sector CHS = cylinder with replacement sector +1, same head as used in replacement sector, same sector as replacement sector

case2) Position information of mirror replacement sector CHS = cylinder with replacement sector +1, (head +1)% (max number) used in replacement sector, same sector as replacement sector

According to case 1), the access rule is set so that the mirror replacement sector paired with the replacement sector has the same head and sector numbers, and only the cylinder number is increased by " 1 ".

In contrast, according to case2), the mirror replacement sector paired with the replacement sector has the same replacement sector and sector number only, increases "1" to the head number used in the replacement sector, and the head number used in the replacement sector is maximum. If the number is shifted to the head of the minimum number, the access rule is set so that the cylinder number is determined to be "1" increased from the cylinder number of the replacement sector.

In an embodiment of the present invention, two examples of determining the position of the mirror replacement sector are provided. However, the present invention is not limited thereto, and the mirror replacement sector may be determined by various access rules.

When the defect is generated during the data write operation by the above method, the spare sector is reallocated to replace the spare sector to write the data to be written to the defect sector, and the replacement sector is also mirrored to the mirror replacement sector paired with the spare sector in the spare area. The same data as the data recorded in " In other words, data to be recorded in the defect sector is recorded in two sectors of the spare area.

Next, a data read process according to the data preservation method of the defect sector in the data storage system according to the present invention will be described with reference to FIG. 4.

The controller 42 determines whether to enter the read mode according to the data read command received from the host device (not shown) (S410).

When entering the read mode, the controller 42 executes the data read mode after moving the converter 16 to the target track to be read from the disc 12 (S420).

It is determined whether an error occurs in the process of reading data (S430). An error in the data read process occurs when the data cannot be read normally even when the retry is performed while changing the parameter values by a predetermined number of times.

When an error occurs in the read process as a result of the determination in step 430 (S430), it is determined whether the sector in which the error has occurred corresponds to the replacement sector reassigned in the spare area (S440).

If an error occurs when data is read from the reassigned replacement sector as a result of the determination in step 440 (S440), the controller 42 searches to move the converter 16 to the mirror replacement sector paired with the error replacement replacement sector. Control (S450). The method of finding the mirror replacement sector position finds the mirror replacement sector position information paired with the replacement sector from the access rule as described in detail in the flowchart of FIG. 3.

Then, the controller 42 controls to read the data stored in the mirror replacement sector (S460).

That is, the data is read by referring to the defect list stored in the RAM 52 during the data reading process. In the process of reading the sector D2 in which the defect is generated, as shown in FIGS. The converter 16 is moved to the replacement sector S129 stored in the defect list to read data stored in the replacement sector S129. However, if an error occurs even when data is read in the replacement sector S129, the mirror replacement sector S129, which is another sector paired with the replacement sector S129 (bold display), is blurred as shown in FIG. 5 (f). The transducer 16 is moved to the position C) to read the data stored in the mirror replacement sector.

If an error occurs in the process of reading the data of the spare sector reallocated to the spare area as described above, the mirror replacement sector, which is another sector paired with the spare sector, is searched for data reading. Accordingly, even if a defect is generated in the replacement sector in the future, data loss is prevented by using the mirror replacement sector.

The invention can be practiced as a method, apparatus, system, or the like. When implemented in software, the constituent means of the present invention are code segments that necessarily perform the necessary work. The program or code segments may be stored in a processor readable medium or transmitted by a computer data signal coupled with a carrier on a transmission medium or network. Processor readable media includes any medium that can store or transmit information. Examples of processor-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memory, erasable ROM (EROM), floppy disks, optical disks, hard disks, optical fiber media, radio frequency (RF) networks, Etc. Computer data signals include any signal that can propagate over transmission media such as electronic network channels, optical fibers, air, electromagnetic fields, RF networks, and the like.

Specific embodiments shown and described in the accompanying drawings are only to be understood as an example of the present invention, not to limit the scope of the invention, but also within the scope of the technical spirit described in the present invention in the technical field to which the present invention belongs As various other changes may occur, it is obvious that the invention is not limited to the specific constructions and arrangements shown or described. That is, it is a matter of course that the present invention can be applied not only to various disk drives including hard disk drives, but also to various kinds of data storage devices.

As described above, according to the present invention, when a defect is generated, data to be recorded in the defect sector is recorded together with the replacement sector and the mirror replacement sector paired with the replacement sector so that the mirror replacement sector can be repaired even if the defect is generated in the future replacement sector. The effect is that data can be preserved without loss.

Claims (6)

In the data processing method in a data storage system, (a) when a defect sector is generated, allocating a replacement sector corresponding to the defect sector in a spare area, and writing data to be written to the defect sector to the replacement sector; And and (b) writing data to be written to the defect sector in a mirror replacement sector paired with the replacement sector in the spare area. The method of claim 1, wherein the position information of the mirror replacement sector is determined by a predetermined access rule from the replacement sector information. The data storage method of claim 1, further comprising: searching for a mirror replacement sector paired with the replacement sector and reading data when an error occurs in the process of reading data stored in the replacement sector. A method for preserving data in a defect sector in a system. In the data storage device, A disk for storing information including a predetermined spare area for reallocating a defect sector; When a defect is generated during data processing, a control process of allocating a replacement sector corresponding to the defect sector in the spare area and writing data to be written to the defect sector to the replacement sector, and the replacement sector in the spare area. A control process of designating a mirror replacement sector to be paired with and writing data to be written to the defect sector to the mirror replacement sector, and if an error occurs in the process of reading data stored in the replacement sector, pairing with the replacement sector. A controller for executing a control process of searching for a mirror replacement sector to form a data; And And a write / read circuit for performing data processing for writing data to or reading data from the disk in accordance with the control process. The disk drive of claim 4, wherein the position information of the mirror replacement sector is determined by a certain access rule from the replacement sector information. In the data processing method in a data storage system, (a) when a defect sector is generated, writing data to be written to the defect sector in the spare sector corresponding to the defect sector in the spare area and a sector paired with the spare sector by a certain access rule, respectively; ; And (b) reading data stored in a sector paired with the replacement sector when an error occurs while reading data stored in the replacement sector. How to preserve your data.

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