JPH05210915A - Disk device - Google Patents

Abstract

PURPOSE:To improve the performance of the disk system where information is recorded by the zone bit system by dynamically rearranging data blocks in optimum zones in accordance with statistical information of access to a medium. CONSTITUTION:When a medium 10 is loaded, contents of an exchange table area 13 and an access count table area 14 on the medium are read out to an exchange table memory 60 and an access count memory 40. At the time of reading/writing data from/in the medium 10, contents of the access count memory 40 are incremented simultaneously with data read/write. Contents of the access count memory 30 for a zone 11 where data is read or written are compared with those for a more outer zone 17; and if data exchange improves the performance of the disk system, data in the zone 11 is exchanged with data in the more outer zone 17. Thus, data blocks whose frequency in access is higher are dynamically moved to zones accessed at a higher speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device used in a computer system, and more particularly to a disk device in consideration of data block arrangement on a disk medium.

[0002]

2. Description of the Related Art First, the structure of a conventional disk device will be described with reference to the drawings, and its problems will be mentioned. FIG. 7 is a block diagram showing an example of a conventional disk device. The conventional disk device 103 is composed of a disk controller 104 and a disk drive 101. The disk drive 101 has a drive unit 21 that physically controls the disk medium 10 and a read / write control unit 20 that reads and writes data on the disk medium 10. Further, the disk controller 104 includes a data buffer memory 50 for temporarily storing the data recorded on the disk medium 10, an error correction unit 70 for performing error correction on the data read from the disk medium 10, an upper system 200.
And a system controller 30 for controlling the entire disk device.

A data write command from the host device 200 is sent to the system controller 30 in the disk controller 102 through the host interface 80. The system controller 30 stores the write data from the higher-level device 200 in the data buffer memory 50,
An error correction code is added using the error correction unit 70, and the result is added to the read / write control unit 2 in the disk drive 101.
0 and the drive unit 21 are used to write to the disk medium 10. When data is written, a verify operation is performed as necessary, and when a write failure occurs, a data block substitute process is performed to improve the reliability of data writing. Further, the recording on the disk medium 10 adopts the zone bit recording method, and when the number of rotations of the medium is constant, the fact that the data transfer rate is different between the outer peripheral portion and the inner peripheral portion is utilized, and the outer peripheral portion has a high speed. The data that needs to be accessed is stored, and the other data is stored in the inner peripheral portion to improve the performance of the entire disk system.

[0004]

In the conventional disk device 103, since the arrangement of the data blocks is determined by the host device 200, when the access frequency of the data existing on the disk medium 10 changes, Unless the upper-level device 200 changes the data arrangement, the performance of the data transfer rate of the entire disk system cannot be improved. In addition, in order for the higher-level device 200 to optimize the data arrangement on the disk medium 10, it is necessary to store the access status of the data on the disk medium 10 inside the higher-level device 200, which is usually large. There is a problem that it is not realistic because it involves overhead. Further, in a system in which the loading / unloading of the disk medium 10 is performed without the intervention of the higher-level device 200, it is difficult for the higher-level device 200 to save the data access status on the disk medium 10. An object of the present invention is to solve the above problem by dynamically rearranging a data block in an optimum zone according to statistical information of access to a disk medium.
It is an object of the present invention to provide a disk device that performs recording by the zone bit method that can improve performance.

[0005]

In order to achieve the above object, a disk device according to the present invention is a disk device using a removable medium. In the disk device, an access information storage area for storing access information to the medium and an arrangement of data blocks are arranged. A data block management area for storing information, and when the medium is loaded into the disk device, the management information is read from the data block management area, and when the medium is ejected, the access information of the data block and the arrangement information of the data block are stored in the medium. It is configured to be saved again above. Further, in the above configuration, the access information storage area and the data block management area can be arranged in each zone on the removable medium. Further, in the above configuration, a memory for storing the contents of the access information storage area and the data block management area is provided, and at the time of reading / writing a data block, the reading / writing of information on the medium is controlled by referring to the contents of the memory. And to control the state of the data blocks stored in the data buffer. Further, in a disk device using zone bit recording, a data block that is frequently accessed can be relocated to the outer zone depending on the contents of the memory. In the above configuration, the rearrangement of the data block can be configured to be processed in the disk device without the intervention of the host device.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a disk device according to the present invention. In the figure, a disk drive 101 is a removable disk medium 10, and a read / write control unit 2 for reading and writing data on the disk medium 10.
0 and the drive unit 21 for physically controlling the disk medium 10. Disk controller 102
Is an access count memory 40 for storing the number of accesses to the data existing on the disk medium 10, a data buffer memory 50 for temporarily storing the data recorded on the disk medium 10, and a data block on the disk medium 10. Exchange table memory 6 for storing the arrangement state
0, error correction of data read from the disk medium 10 and an error correction unit 70 that adds an error correction code when writing data to the disk medium 10, an upper interface 80 for interfacing with an external system, and control of the entire disk device It includes a system controller 30 for performing. The disk device 100 is composed of a disk controller 102 and a disk drive 101.

FIG. 2 is a diagram showing an arrangement of data on a disk medium when data is recorded by zone bit recording. This figure shows the disc area on the disc medium 10 by exploding for convenience.
5, 16 and 17 are zones obtained by dividing the data area into n in the radial direction. Of these zones, 11 is the innermost zone, 15 is the zone adjacent to the innermost zone 11, 17
Indicates the outermost zone, and 16 indicates a zone adjacent to the outermost zone. A sector 9 is a recording unit of data in the zone. Zone 1 to outer zone n-2
Zones up to are omitted in this figure. As is clear from this figure, the innermost zone 11 and the outermost zone 17 are used in a disk device that performs zone bit recording.
The outermost zone 17 has more sectors 9 per track.

FIG. 3 is a diagram showing the arrangement of data in the zones on the disk medium 10. In the figure, reference numeral 12 is an area for storing user data, 13 is an exchange table area for recording the arrangement state of data blocks in the zone on the disk medium 10, and 14 is access information for the data blocks on the disk medium 10. This is an access count table area.

FIG. 4 is a diagram showing the structure of the exchange table memory in the disk controller 102. The exchange table memory 60 includes exchange table entries for storing arrangement information of data blocks on the disk medium 10.
The position of the exchange table entry 61 in the exchange table memory 60 corresponds to the logical position of the data block on the disk medium 10, and the content thereof indicates the physical position on the medium.

FIG. 5 is a diagram showing the configuration of the access count memory in the disk controller 102. The access count memory 40 includes an access count entry 41 that stores the number of accesses to the data block on the disk medium 10. The position of the access count entry 41 in the access count memory 40 corresponds to the logical position of the data block on the disk medium 10, and the content thereof indicates the number of times of access to the data block.

FIG. 6 is a diagram showing the structure of the access count entry. The access count entry 41 includes a read count 43 for storing the number of read times for the data block on the disk medium 10 and a write count 42 for storing the number of write times for the data block on the disk medium 10.

Next, the operation will be described with reference to these figures.
When the disk medium 10 is attached to the disk device 100,
The system controller 30 in the disk controller 102 controls the drive unit 21 and the read / write control unit 20 of the disk drive 101, and the exchange table area 13 and the access count in each zone 11, 15, 16 and 17 on the disk medium 10. The contents of the area 14 are read and stored in the data buffer memory 50 in the disk controller 102. The read contents are subjected to error correction by the error correction unit 70, and the exchange table memory 60
And the access count memory 40 respectively.

From the disk device 100 to the disk medium 10
When ejecting, the system controller 30 in the disk controller 102 transfers the contents of the exchange table memory 60 to the data buffer memory 50, and the error correction unit 70
Is used to add an error correction code, and is written in the exchange table area 13 on the disk medium 10 by the drive unit 21 and the read / write control unit 20. Next, the contents of the access count memory 40 are transferred to the data buffer memory 50, an error correction code is added by the error correction unit 70, and the data is written in the access count region 14 on the disk medium 10 by the drive unit 21 and the read / write control unit 20. ..

Next, the operation in response to the data read command from the upper level device 200 will be described. The data block requested to be read by the higher-level device will be described as existing in the 0 zone 11 in FIG. In the following description, n
Unless the data block exists in the -1 zone 17, the process when the data block exists in the 0 zone 11 is similarly performed when the data block exists in the 1 zone 15 and thereafter. Further, the position of the data block existing on the disk medium 10 is called a physical position, and the position of the data block requested to be read by the host device is called a logical position.

The data read command issued by the host device 200 reaches the system controller 30 through the host interface 80. The system controller 30 finds at which position on the disk medium 10 the data block to be read exists based on the contents of the exchange table memory 60. The system controller 30 reads the data block on the disk medium 10 by the drive unit 21 and the read / write control unit 20, transfers it to the data buffer memory 50, corrects the error by the error correction unit 70, and transfers it to the higher level device 200 through the higher level interface 80. Transfer data. Hereinafter, this data block will be referred to as a first data block. At this time, the content of the read count 42 of the access count entry 41 in the access count memory 40 corresponding to the physical position of the first data block is incremented. Further, the read count 4 of the access count entry 41 corresponding to the first data block
2 zone and 0 zone where the first data block exists 1
The contents of the read count 42 of the access count entry 41 of the one zone 15 on the outer periphery of 1 are compared.

At this time, if the read count 42 of the access count entry 41 corresponding to one zone 15 has a smaller value than the read count 42 of the access count entry 41 corresponding to the first data block. For example, the data block replacement process described below is performed. Hereinafter, the data block to be replaced is referred to as a second data block.

The data block replacement process at the time of data reading will be described. The system controller 30 transfers the contents of the second data block to the data buffer memory 50 by the drive unit 21 and the read / write control unit 20, and the error correction unit 70 performs error correction. Next, the system controller 30 adds an error correction code to the first data block by the error correction unit 70, and the 0 zone 1
1, the content of the second data block is located at the position of the data block where the first data block exists, and the content of the first data block is located at the position of the data block where the second data block of 1 zone 15 is located. The disk medium 10 by controlling the drive unit 21 and the read / write control unit 20.
Write in.

Further, the exchange table entry 61 in the exchange table memory 60 is exchanged between the first data block and the second data block, and the contents of the access count entry 41 corresponding to the first data block. And the contents of the access count entry 41 corresponding to the second data block are exchanged.

Next, the operation in response to the data write command from the upper level device 200 will be described. Note that, similar to the description of the operation for the read command, the data block requested to be written by the host device will be described as existing in the 0 zone 11 in FIG. In the following description, n-1 zone 1
0 zone 11 except when data block exists in 7
Processing when there is a data block in 1 zone 1
The same is done when there are data blocks after 5. The position of a data block existing on the disk medium 10 is called a physical position, and the position of a data block requested to be written by a host device is called a logical position.

The data write command issued by the host device 200 reaches the system controller 30 through the host interface 80. The system controller 30 receives the data to be written from the host device 200, stores it in the data buffer memory 50, and adds the error correction code by the error correction unit 70. Next, the system controller 30 determines at which position on the disk medium 10 the data block to be written exists based on the contents of the exchange table memory 60. The system controller 30 has a drive unit 21.
The read / write control unit 20 controls the disk medium 10
Write the data block on top. Hereinafter, this data block is referred to as a third data block.

At this time, the content of the write count 43 of the access count entry 41 in the access count memory 40 corresponding to the physical position of the third data block is incremented. Further, the write count 43 of the access count entry 41 of the 1 zone 15 outside the 0 zone 11 in which the third data block is written is compared. At this time, of the contents of the write count 43 of the access count entry 41 corresponding to 1 zone 15,
If it has a value smaller than the content of the write count 43 of the access count entry 41 corresponding to the third data block, the data block replacement process described below is performed. Hereinafter, the data block to be replaced is referred to as the fourth data block.

A data block replacement process at the time of data writing will be described. The system controller 30 transfers the contents of the fourth data block to the data buffer memory 50 by the drive unit 21 and the read / write control unit 20, the error correction unit 70 performs error correction, and the error correction unit 70 again outputs the error correction code. Append to data block. Next, the system controller 30 is 0 zone 1
1, the content of the fourth data block is located at the position of the data block where the third data block exists, and the content of the third data block is located at the position of the data block where the second data block of 1 zone 15 is located. The disk medium 10 by controlling the drive unit 21 and the read / write control unit 20.
Write in.

Furthermore, the exchange table entry 61 in the exchange table memory 60 is exchanged between the third data block and the fourth data block, and the contents of the access count entry 41 corresponding to the third data block are exchanged. And the contents of the access count entry 41 corresponding to the fourth data block are exchanged. By performing the above processing, the data block having a high access frequency is moved to the outer peripheral portion having a high data transfer rate by the system controller 30.

[0024]

As described above, the disk device according to the present invention is configured to internally store the data access status and rearrange the data layout on the disk medium according to the data access status. As a result, frequently accessed data are concentrated on the outer peripheral portion, and the data transfer speed of the disk device can be improved in performance.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a disk device according to the present invention.

FIG. 2 is a diagram showing an arrangement of zones on a medium.

FIG. 3 is a diagram showing an arrangement of data in a zone.

FIG. 4 is a diagram showing an arrangement of data in an exchange table memory.

FIG. 5 is a diagram showing an arrangement of data in an access count memory.

FIG. 6 is a diagram showing an arrangement of data in an access count entry.

FIG. 7 is a block diagram showing an example of a conventional disk device.

[Explanation of symbols]

 9 ... Sector 10 ... Medium 11 ... 0 zone 12 ... User data area 13 ... Exchange table area 14 ... Access count table area 15 ... 1 zone 16 ... n-2 zone 17 ... n-1 zone 20 ... Read / write control section 21 ... Drive unit 30 ... System controller 40 ... Access count memory 41 ... Access count entry 42 ... Read count 43 ... Write count 50 ... Exchange memory 60 ... Data buffer memory 61 ... Exchange memory memory 70 ... Error correction unit 80 ... Upper interface 100, 103 ... Disk device 101 ... Disk drives 102, 104 ... Disk controller 200 ... Upper device

Claims (5)

[Claims] 1. A disk device using a removable medium, comprising: an access information storage area for storing access information for the medium; and a data block management area for storing data block arrangement information. A disc characterized in that when the medium is loaded, the management information is read from the data block management area, and when the disc medium is ejected, the access information of the data block and the arrangement information of the data block are re-stored on the medium. apparatus. 2. The disk device according to claim 1, wherein the access information storage area and the data block management area are arranged for each zone on a removable medium. 3. A memory for storing the contents of the access information storage area and the data block management area is provided, and when the data block is read or written, the content of the memory is referenced to control the reading or writing of information on the medium. 2. The disk device according to claim 1, wherein a state of a data block stored in the data buffer is controlled. 4. A disk device adopting the zone bit recording method, wherein a data block having a high access frequency is relocated to an outer zone depending on the contents of the memory. .. 5. The disk device according to claim 4, wherein the relocation of the data block is configured to be processed in the disk device without intervention of a host device.