JPH0580945A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To increase the processing speed by shortening the mean rotation wait time of the disk device when a mirror disk is constituted by using plural disk devices. CONSTITUTION:The magnetic disk device 100 consists of a high-order interface control circuit 10 which corresponds to a host 200 across a host interface 300, a microcomputer 20 which controls the writing and reading processing of data, a data buffer circuit 30 which fetches write data from the host 200, a low-order interface control circuit 140 which performs the writing and reading processing of the disk device I60 and a disk device II70, and a low-order interface control circuit II150.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device used in an information processing system.

[0002]

2. Description of the Related Art Conventionally, a magnetic disk drive has been a method of writing one data at the same location on a plurality of disks which are rotationally synchronized.

[0003]

In the above-mentioned magnetic disk drive system, the reliability of data is high, but the average rotation waiting time is the same as in the case of one disk drive, and the processing speed is not improved. There was a point.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a magnetic disk device which shortens the average rotation waiting time of the disk device and increases the processing speed.

[0005]

A magnetic disk device according to the present invention synchronizes the rotations of a plurality of magnetic disk devices, and
A means to make the relative position of DEX and HEAD the same in all disk devices, a means to format each disk device so that the relative position of the sector from INDEX differs for each disk device, and a disk from a command from the control unit. When writing data to the device, write the write data to the buffer while writing the same data to all the disks, and when the writing is completed in any of the disk devices, report the end of writing to the control unit and A means for writing data in the buffer to the disk device which has not been completed, and a case where data is read from the disk device by a command from the control unit,
It has means for transferring the data of the disk device which has reached the target sector first to the control unit.

[0006]

According to the above configuration, the sector is formatted so that the relative position from the INDEX is different for each disk device, the same data is written to all the disks, and the writing ends immediately when the writing is completed by either disk device. Is reported to the control unit and the other disk devices continue writing from the buffer, while when reading data, the data of the disk that reaches the target sector first is transferred to the control unit. The average rotation waiting time of the disk device can be shortened.

[0007]

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

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

In FIG. 1, the magnetic disk device 100 is
Upper interface control circuit 10 with host computer 200, microcomputer 20, data buffer circuit 30 for fetching disk device write data, lower interface control circuit I4 with each disk device
0, a lower interface control circuit II50, a disk device I60, and a disk device II70.

Further, the magnetic disk device 100 is connected to the host 200 through the host interface 300, the disk device I60 and the disk device II70 have 14 sectors per track, and INDEX and HEAD are provided by a rotation synchronizing signal. The rotation is synchronized so that the relative positions of the two are the same.

FIG. 2 is a format diagram of the magnetic disk device of the present invention.

The operation of the magnetic disk device configured as described above is as follows.

Upper interface 3 from host 200
When a format command is input to the magnetic disk device 100 via 00, the microcomputer 20 issues a format command to the lower interface control circuit I40 and the lower interface control circuit II50. When receiving the format command, the lower interface control circuit I40 and the lower interface control circuit II50 respectively format the disk device I60 and the disk device II70 so that the sector position with respect to INDEX is shifted by a half track as shown in FIG. When the completion of the formatting is reported from the lower interface control unit I40 and the lower interface control unit II50, the microcomputer 20 determines that the upper interface control circuit 1
0 to host 2 via upper interface 300
Report the end of formatting to 00. Host 2
00, when a write command is input to the magnetic disk device 100 through the upper interface 300, the microcomputer 20 waits for both the lower interface control circuit I40 and the lower interface control circuit II50 to finish executing the command. The host 20 is connected to the host interface control circuit 10 and the data buffer circuit 30.
After instructing to write data from 0, a write command is issued to the lower interface control circuit I40 and the lower interface control circuit II50. When the lower interface control circuit I40 and the lower interface control circuit II50 receive the write command, they search the target sector for the disk device I60 and the disk device II70, respectively, and when they detect the target sector, they receive the write data from the data buffer circuit 30. Start writing. At this time, if the disk device I60 finishes writing before the disk device II70, the lower interface control circuit I40 notifies the microcomputer 20 of the end of the write command. When the writing end is notified, the microcomputer 20 causes the upper interface control circuit 10 to
The end of writing is reported to the host 200 via 0.
The disk device II70 which has not completed writing receives the write data from the data buffer circuit 30 and continues writing, and when the writing is completed, the lower interface control circuit II50 notifies the microcomputer 20 of the end of the write command. Similarly, if the disk device II70 finishes writing before the disk device I60, the lower interface control circuit II50 notifies the microcomputer 20 of the end of the write command. When notified of the end of writing, the microcomputer 20 reports the end of writing to the host 200 via the upper interface 300 by the upper interface control circuit 10. Disk device I6 for which writing has not been completed
0 receives write data from the data buffer circuit 30 and continues writing, and when the writing is completed, the lower interface control circuit I40 causes the microcomputer 2 to
0 is notified of the end of the write command.

Next, when a read command is input from the host 200 to the magnetic disk device 100 via the upper interface 300, the microcomputer 20 causes the lower interface control circuit I40 and the lower interface control circuit II50 to execute the command. After waiting for the completion, a read command is issued to the lower interface control circuit I40 and the lower interface control circuit II50. When the lower interface control circuit I40 and the lower interface control circuit II50 receive the read command, they search the first sector of the data to be read to the disk device I60 and the disk device II70, respectively. When the lower interface control circuit I40 finds the first sector before the lower interface control circuit II50, the microcomputer 20 immediately cancels the read command of the lower interface control circuit II50. The lower interface control circuit I40 starts reading data, and the upper interface control circuit 10 transfers the read data to the host 200 via the upper interface 300. If an error occurs in the read data, the microcomputer 20 immediately cancels the read command of the lower interface control circuit I40, and the microcomputer 20 causes the lower interface control circuit I40 to stop.
The read command is issued to the II 50, the lower interface control circuit II 50 executes the data read command, and the upper interface control circuit 10 passes the read data to the host 200 via the upper interface 300. When the transfer of all the read data is completed, the microcomputer 20 sets the upper interface control circuit 1
0 to host 2 via upper interface 300
The end of the read command is reported to 00. Similarly, when the lower-order interface control circuit II50 finds the first sector before the lower-order interface control circuit I40, the microcomputer 20 determines the lower-order interface control circuit I4.
Immediately abort the read instruction of 0. The lower interface control circuit II50 starts reading data, and the upper interface control circuit 10 passes the read data to the host 200 via the upper interface 300. If an error occurs in the read data, the microcomputer 20 determines the lower interface control circuit.
Immediately stop the read command of II50, the microcomputer 20 issues a read command to the lower interface control circuit I40, and the lower interface control circuit I4
0 executes a data read command and passes the read data to the host 200 via the upper interface 300 by the upper interface control circuit 10. When the transfer of all the read data is completed, the microcomputer 20 reports the completion of the read command to the host 200 via the upper interface 300 by the upper interface control circuit 10.

In this embodiment, the case where there are two disk devices has been described, but the number of disk devices is N (N =
The same applies to the case of 3, 4, 5) units.

[0016]

As described above, by adopting the magnetic disk device of the present invention, it is possible to improve the reliability of data and reduce the average rotation waiting time to one-tenth of the number of disk devices.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a magnetic disk device showing an embodiment of the present invention.

FIG. 2 is a format in the magnetic disk device of the present invention.

[Explanation of symbols]

 10 Upper Interface Control Circuit 20 Microcomputer 30 Data Buffer Circuit 40 Lower Interface Control Circuit I 50 Lower Interface Control Circuit II 60 Disk Device I 70 Disk Device II 100 Magnetic Disk Device 200 Host 300 Upper Interface

Claims (1)

[Claims] 1. A means for synchronizing the rotations of a plurality of magnetic disk devices so that the relative positions of INDEX and HEAD are the same in all the disk devices, and the relative position of the sector of each disk device from the INDEX is the disk device. When writing data to the disk device in response to a command from the control unit and a format to be different for each, write data is written to the buffer while writing the same data to all disks, and the writing is completed in either disk device At the time of writing, it reports to the control unit that writing has been completed, and for a disk device that has not completed writing, means for writing the data in the buffer, and a command from the control unit to send data from the disk device. When reading, the data of the disk device that reached the target sector first is A magnetic disk drive having means for transferring to the control unit.