JP2885776B1 - Mirror disk control method and mirror disk control device - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a mirror disk control method and a mirror disk control device which can increase the data write speed while increasing the data read speed. SOLUTION: In a mirror disk control device for controlling each disk 11 to write the same data to a plurality of disks 11 or to read the written data, each of the disks 11 has a different state from that at the time of data reading. Control circuit 14 for controlling rotation
a and 14b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mirror disk control method and a mirror disk control device, and more particularly to a mirror disk control method and a mirror disk control device in mirroring for writing the same data to a plurality of disks.

[0002]

2. Description of the Related Art Conventionally, a plurality of disks as storage media are provided, and a device for writing or reading data to or from this disk is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-31311.
There is known a disk array device disclosed in Japanese Patent Application Laid-Open No. 5-205, or a data access device and a distributed database system disclosed in Japanese Patent Application Laid-Open No. 7-302173.

In this disk array device, a plurality of disk devices are installed in parallel, each disk device is provided with a rotation synchronizing circuit, and a plurality of disk devices are rotated and synchronized by a rotation synchronizing signal generation circuit. . Therefore,
The average rotation waiting time of the disk is reduced to 回 転 rotation, and the data access time can be reduced.

Further, the data access device and the distributed database system have two hard disk devices (HDDs).
The same data is written to both HDDs and the data is read out from the HDD which can be read out earlier by performing the connection by overlapping and performing the synchronous operation by shifting each HDD by a half turn according to the synchronization signal. Therefore, the reliability of data is improved by mirroring the HDD, and the rotation waiting time of data access can be reduced to half by shifting the rotation of the HDD.

As described above, in each of the above-described conventional devices, in order to increase the data reading speed, one of the rotations of the plurality of disk devices (or two HDDs) is shifted by, for example, 回 転 rotation with respect to the other. By shifting the timing at which the target sector on the disk passes the write / read head, and adopting the data of the disk device (HDD) through which the sector passes earlier, the read speed of the entire device can be increased. I was earlier.

[0006]

However, in each of the above conventional examples, the data reading speed could be increased, but the data writing speed was inevitably reduced. That is, in the case of writing, the writing must be terminated in any disk device (HDD), and the writing does not end unless the writing of the data whose sector passes late is not completed.

An object of the present invention is to provide a mirror disk control method and a mirror disk control device which can increase the data write speed while increasing the data read speed.

[0008]

In order to achieve the above object, a method of controlling a mirror disk according to the present invention comprises the steps of: rotating the respective disks to write the same data to a plurality of disks or to read the written data; The mirror disk control method for controlling is characterized in that when data is written, the rotation of each disk is controlled to a state different from that when data is read.

With the above configuration, it is possible to control the rotation of each disk at the time of writing data, and to set each disk at a state different from that at the time of reading data.
For this reason, even if the speed is shifted between the disks at the time of data reading, the difference is eliminated at the time of data writing, and it is possible to prevent a decrease in the data writing speed while increasing the data reading speed.

Further, the mirror disk control method according to the present invention can realize the above-mentioned mirror disk control method.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a mirror disk control device according to an embodiment of the present invention. FIG. 1 (a) is an explanatory diagram in which both disks are shifted by 回 転 rotation, and FIG. FIG. 4 is an explanatory diagram in a state where the disc has eliminated the rotational displacement. As shown in FIGS. 1A and 1B, the mirror disk control device 10 includes two disk drives 12a and 12b on which disks 11 are rotatably mounted. A recording area (not shown) composed of tracks divided into a plurality of sectors is concentrically arranged on a disk 11 which is a disk-shaped recording medium.
The index 11a is recorded as an index of the rotation state of.

Each of the disk drives 12a and 12b has
The disc 1 faces the recording area of the disc 11
1 are provided with write / read heads 13a and 13b for writing (writing) data or reading (reading) data.

Each of the disk drives 12a, 12b
Include rotation control circuits 14a, 1 for controlling the driving state.
4b is connected to each of the rotation control circuits 14a and 14
b, the rotation of the disk 11 driven by each of the disk drives 12a and 12b is individually controlled. Each of the rotation control circuits 14a and 14b is provided with detection means (not shown) such as a detection sensor for detecting the rotation state of the disk 11.

A computer circuit 15 is connected to each of the rotation control circuits 14a and 14b, and each of the rotation control circuits 14a and 14b is operated by an operation control signal from the computer circuit 15.
The operation of each of b is controlled. The computer circuit 15 has a function of managing the displacement of the disk 11 driven by each of the disk drives 12a and 12b, and according to an operation command (command) to be input, a rotation control circuit 14a.
Alternatively, an operation control signal is output to the rotation control circuit 14b so as to shift one of the disks 11 that are driven to rotate by １ ／ rotation with respect to the other.

Therefore, according to the operation control signal from the computer circuit 15, the disk 11 on the disk drive 12a is
The disk 11 can be shifted by 回 転 rotation with respect to the upper disk 11 (see the index 11a in (a)). Similarly, when data is written to each disk 11, each disk 11 is different from when data is read. State, eg 1/2
The state in which the rotation has been shifted may be eliminated (see the index 11a in (b)).

Next, the operation of the mirror disk control device will be described. As shown in FIG. 1A, when reading data,
One of the disks 11 driven by each of the disk drives 12a and 12b is shifted by 回 転 rotation with respect to the other.
Therefore, at the time of data reading, of the two disks 11,
By reading and transferring data from the disk 11 on which the target sector has reached one of the heads 13a and 13b earlier, data access can be speeded up.

On the other hand, as shown in FIG. 1B, at the time of writing data, the disk 11 driven by each of the disk drives 12a and 12b further shifts the disk 11 which has been shifted by 1/2 rotation at the time of data reading. / 2 rotations, the two indexes 11a are aligned, and the rotation deviation between the two disks 11 is eliminated. Therefore, at the time of data writing, data can be simultaneously written to both disks 11 driven by both disk drives 12a and 12b. For this reason, since it is not necessary to wait for the completion of data writing to both disks 11, which is necessary when there is a rotational deviation between both disks 11, it is possible to prevent the data writing speed from becoming slow. .

When writing the data, both disks 1
A comparison will be made with a case where the rotation deviation of No. 1 is not eliminated. At the time of reading data, since both disks 11 have a rotation shift of 1/2, it takes an average of 1/4 turn until the target sector passes one of the heads 13a and 13b. On the other hand, the disk 11 which passes earlier needs only 1/4 rotation on average, while the other disk 11 passes after being further rotated by 1/2 rotation thereafter. That is, both target sectors of both disks 11 driven by the two disk drives 12a and 12b
It takes an average of 3/4 rotation to pass through a and 13b.

On the other hand, in the case of the mirror disk control device 10 according to the present invention, since the rotational deviation between the two disks 11 is eliminated at the time of data writing, it is driven by the two disk drives 12a and 12b. Both discs 1
The average rotation wait until one target sector passes through both heads 13a and 13b is 1/2 rotation. Thereby, high-speed access is possible as compared with the case where the rotation deviation of both disks 11 is not eliminated during data writing.

As described above, when data is read, one of the disks 11 driven by the disk drives 12a and 12b is shifted by １ ／ rotation with respect to the other, and when data is written, the rotation of both disks 11 is shifted. By eliminating this, it is possible to reduce the rotation waiting time at the time of writing data and write data to both disks 11 at the same time. In other words, by shifting the disk position in accordance with the reading or writing situation, it is possible to access both disks more appropriately than before, and to reduce the writing speed at the time of data writing while speeding up the data reading. be able to.

In the above embodiment, each of the two rotation control circuits 14a and 14b is provided with a rotation control function capable of displacing the two disks 11 by 1/2 rotation. Only one of the disk drives 12a and 12b may be provided with a rotation control function to control one of the disk drives 12a and 12b. In this case, the mirror disk control device can be configured with a smaller system.

The number of disks on which data is written or read is not limited to two, but may be three or more, and the rotational displacement is not limited to half.

[0024]

As described above, according to the present invention,
When writing data, control the rotation of each disk,
Since each disk can be set to a different state from that when reading data, even if the speed is different between the disks when reading data, the difference is resolved when writing data, reducing the rotation waiting time, It becomes possible to write. As a result, more appropriate access to both disks becomes possible, and a reduction in the writing speed at the time of data writing can be prevented while speeding up data reading.

Further, the mirror disk control method according to the present invention can realize the above-mentioned mirror disk control method.

[Brief description of the drawings]

FIG. 1 shows a schematic configuration of a mirror disk control device according to an embodiment of the present invention. FIG. 1 (a) is an explanatory diagram in which both disks are shifted by １ ／ rotation, and FIG. It is an explanatory view in a state where a shift is canceled.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Mirror disk control device 11 Disk 12a, 12b Disk drive 11a Index 13a, 13b Head 14a, 14b Rotation control circuit 15 Computer circuit

Claims (7)

(57) [Claims] 1. A mirror disk control method for controlling the rotation of each disk to write the same data to a plurality of disks or to read the written data, the method comprising the steps of: A mirror disk control method characterized by performing rotation control to a state. 2. When data is read, each of said disks is 1 /
2. The mirror disk control method according to claim 1, wherein the rotation is shifted by two rotations. 3. The mirror disk control method according to claim 2, wherein a deviation at the time of reading data from each of said disks during data writing is eliminated. 4. A mirror disk control device for controlling each of said disks in order to write the same data to a plurality of disks or to read the written data, wherein each of said disks is in a state different from the time of reading data when writing data. A mirror disk control device comprising: a rotation control means for controlling rotation of the mirror disk. 5. The method according to claim 1, wherein said rotation control means includes:
5. The mirror disk control device according to claim 4, wherein the rotation of each of the disks is controlled so as to eliminate a deviation at the time of data reading. 6. The mirror disk control device according to claim 4, wherein said rotation control means detects an index from each of said disks and controls rotation of each of said disks. 7. The mirror disk control device according to claim 4, wherein two of said disks are provided, and said rotation control means controls the rotation of one of said two disks. .