JP3087367B2 - How to specify the head position - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for designating a head position in a drive device for driving a disk device, and more particularly to a method for driving a disk device which automatically switches to a substitute track by hardware when a track is defective. The present invention relates to a method of driving a disk device in which requests to disk devices are grouped for each cylinder number, processed in the direction of cylinder numbers in one direction, proceed to the end, and then proceed in a different direction.

[0002]

2. Description of the Related Art Conventionally, this kind ofHow to specify the head position
Indicates that the drive that drives the disk drive is
And wait for the received request, and in one direction in the order of cylinder number
Process sequentially, and when it reaches the end, reverse the direction
Head to track
The aim is to minimize the time to search.

This will be described with reference to FIG. FIG. 4A is an explanatory diagram showing an example of the order of processing the cylinder numbers in the forward direction, and FIG. 4B is an explanatory diagram showing an example of the order of the processing in the reverse direction. As shown in FIG. 4A, the direction flag 0 means forward processing, and cylinder numbers 0, 2, 3, 22, and 24 are waiting for a request. Accordingly, the drive device designates the head position to the disk device in the order of cylinder numbers 0, 2, 3, 22, and 24.

In FIG. 4 (B), after the request is processed by designating the head to the last cylinder number 24, the drive unit converts the direction flag into binary code 1 and outputs the cylinder number 21 having the request wait. , 3, 1, 0 are sequentially specified in the reverse order of the numbers.

FIG. 4C is an explanatory diagram showing an example in which a defective track is present at cylinder number 1 and cylinder number A is used. The replacement cylinder is the oldest position, and the controller of the disk device that found the defect is hardware, and when the position of the head of cylinder number 1 is designated, the head is automatically moved to cylinder number A and the data is transferred. writing·
Perform a read.

Accordingly, the drive unit is provided with cylinder numbers 0, 1,
When sequentially designating 2, 22, and 24, the head of the disk drive moves to cylinder number A instead of cylinder number 1 and then returns to cylinder number 2. That is, it takes a reciprocating cylinder position search time for the head to move to cylinder number A and return to cylinder 2.

[0007]

In the above-described conventional head position specifying method, a defective track is found on the disk device side even though the drive device specifies the position so as to minimize the movement of the head. When the replacement cylinder is used, for example, the replacement cylinder at the outer position is automatically used. Therefore, there is a problem that the operation efficiency of the head is poor, such as a long moving time and a change in the moving direction on the way.

An object of the present invention, that it has alternative defective track know in cylinder number search time of the head, by specifying the head of the cylinder number of the defective track by replacing the alternative cylinder number, heads to solve the above problems
It is an object of the present invention to provide a method for specifying a position of a key .

[0009]

SUMMARY OF THE INVENTION A head position according to the present invention is provided.
The location specification method drives a disk device that automatically switches to an alternate track by hardware when a track is defective, collects requests for this disk device for each cylinder number, and processes in one direction in the order of cylinder numbers. Drive to the end and then change direction to proceed with the process
In the head position specifying method , when the drive device is driven by specifying the position of the head with the cylinder number including the specified track number, the driving movement time of the head to this cylinder number is measured and exceeds the expected search time value. At this time, it is determined that the specified track has been replaced from the measured value, the cylinder number of the replacement track is determined, the replacement cylinder number for the defective track is recorded in the replacement track management table, and the request for the specified track number is processed. ,
The received request for the track number is first checked in the alternative track management table, and if there is a record, the request is waited for with the recorded alternative cylinder number.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.

As shown in the figure, a disk drive 10 is connected to a disk drive 20 via a disk controller 21 for controlling the disk drive 20, specifies a cylinder number, and places a head on a track of a disk for inputting and outputting data. Position.

The drive unit 10 includes a request receiving unit 11, a common data unit 12, a request processing unit 13, and a disk drive unit 14.
, A search time measuring unit 15 is newly added. The common data section 12 newly adds the replacement track management table 1 to the request waiting table 16.
Seven. That is, the search time measuring unit 15 and the alternative track management table 17 are added to the conventional one.

The request receiving unit 11 receives the request and causes the cylinder number of the common data unit 12 to wait for the request.

The request processing section 13 stores the request waiting table 16 in the common data section 12 in the forward direction from the youngest to the oldest or in the reverse direction from the oldest to the youngest in accordance with the instruction of the direction flag. After the data is taken out and the head position is specified to the disk device 20 via the disk drive unit 14, data is input / output according to the request.

The search time measuring unit 15 receives the start and end signals of the movement of the head from the request processing unit 13 and measures the time until the head searches for the specified track.

The replacement track management table 17 records that the defective track number 1 is using the track of the cylinder having the replacement cylinder number A.

Here, the movement of the head of the disk drive will be described with reference to FIG. 2 and FIG. FIG. 2A shows an example in which the cylinder number A is used by the disk control device 21 because the defective track is included in the cylinder number 1.

That is, cylinder numbers 0, 1, 2, 23
When the request processing unit 13 designates the cylinder number 1 to the disk device 20 following the processing of the cylinder number 0, the request processing unit 13 designates the cylinder number 1 to the disk device 20 when the cylinder number 1 is substituted and the request is waited for the cylinder number A. Moves from cylinder number 0 to cylinder number A (position corresponding to 25) to process the request, and then moves to cylinder number 2
Is specified, the head moves again with a long head return time.

Therefore, the search time measuring unit 15 measures the time from when the head input signal from the request processing unit 13 indicating the start and end of the movement of the head to when the head searches for the specified cylinder.

The request processing unit 13 knows from this measured value that the cylinder number 1 is used in place of the cylinder number A, and in the replacement track management table 17, the replacement cylinder number A And the request for the defective track number 1 in the request waiting table 16 moves to the cylinder number A.

Thereafter, the request receiving section 11 waits for the received request for the defective track number 1 at the cylinder number A based on the alternative track management table 17. Therefore, there is no request waiting for cylinder number 1 and cylinder number 25
(A position) has a request waiting. This state is shown in FIG.
Is shown in

As shown in FIGS. 1 and 2B, the common data section 12 does not have a request waiting for the cylinder number 1,
Since it has the cylinder number A (25), the request processing unit 13
Specifies the cylinder numbers 0, 2, 23, and 25 waiting for a request in order. Therefore, as shown in FIG. 2A, there is no longer any head operation that proceeds for a long time and returns.

FIG. 3 is an explanatory diagram showing an example of the operation of the request processing unit 13 in FIG.

FIG. 3A shows an example in the case of a forward direction flag. As shown in the figure, when the cylinder number C2 is designated following the processing of the cylinder number C1, the head is moved to the alternative cylinder number CA, and the measurement time t, the head setting time TR at the start and end of the search, In addition, in the case of the head movement time TS per one cylinder, the number of numbers proceeding to the measurement time t is as follows.

(T-TR) / TS Accordingly, the number difference D from the cylinder number C2 to the cylinder number CA is given by the following equation.

(T-TR) / TS- (C2-C1) = D That is, the cylinder number CA is obtained by the following equation.

CA = C1 + (t-TR) / TS FIG. 3B is an explanatory view showing an example in the reverse forward direction of FIG. 3A, and the number difference D in the above equation becomes the following equation. It is the same as the formula.

D = (t−TR) / TS + (C1−C2) = (t−TR) / TS− (C2−C1) In the present embodiment, it is shown and described that the request waiting is moved from the replaced cylinder number. However, the processing procedure may be such that the request waiting table and the alternative track management table are associated with each request processing.

[0029]

As described above, according to the present invention, the cylinder position of the substitute track is determined from the measured value by measuring the head movement time, recorded in the substitute track management table, and the request for the defective track is substituted for the substitute cylinder. In this case, the head movement to the disk device can be designated in one direction, so that it is possible to prevent an operation of returning the disk in the middle and to reduce the search time for the designated track.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a state at the time of replacement detection and a state after detection in FIG. 1;

FIG. 3 is an explanatory diagram showing a calculation example of an alternative cylinder number.

FIG. 4 is a state explanatory view showing an example of the related art corresponding to FIG. 2;

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 drive device 11 request receiving unit 12 common data unit 13 request processing unit 15 search time measuring unit 16 request waiting table 17 alternative track management table 20 disk device

Claims (1)

(57) [Claims] 1. A disk drive which automatically switches to a substitute track by hardware when a track is defective is driven, requests for the disk drive are grouped by cylinder number, and processed in one direction in the order of cylinder numbers. Drive to the end and then change direction to proceed with the process
In the head position specifying method , when the drive device is driven by specifying the head position with the cylinder number including the specified track number, the head moving search time to the cylinder number is measured and exceeds the expected search time value. At this time, it is determined that the designated track has been replaced based on the measured value, the cylinder number of the replacement track is determined, the replacement cylinder number for the defective track is recorded in the replacement track management table, and the request for the specified track number is processed. The head position is characterized by first examining the received track number request in the alternative track management table and, when there is a record, waiting for the request with the recorded alternative cylinder number.
Placement specification method .