JPH08171460A - Magnetic disk controller - Google Patents

Abstract

PURPOSE: To reduce the duplex processing operation of a magnetic disk device for which an OS is interposed and to improve the throughput of the entire system. CONSTITUTION: The control part 1 of this magnetic disk controller 300 transfers data between the magnetic disk device 3 through an interface 20 and writes the same data as the data written in the magnetic disk device 2 in the magnetic disk device 3 as well. At the time of read, the data are transferred between a main memory unit 200 through the interface 10. Also, when the data of the magnetic disk device 2 can not be normally read, the data of the magnetic disk device 3 are read through the interface 20, the data are transferred to the magnetic disk controller 300 and restoration is performed so as to correctly read the data of the magnetic disk device 2 by using the data. Thus, the burdens of the OS and the magnetic disk controller 300 are reduced and the throughput of the entire system is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk control device, and more particularly to a magnetic disk control device which is connected to a plurality of magnetic disk devices to perform data duplication processing.

[0002]

2. Description of the Related Art Conventionally, a data duplication process by a magnetic disk device called a mirrored disk is performed in the same manner as a normal data transfer from a magnetic disk control device to a magnetic disk device under the control of an OS. The same data is transferred to other magnetic disk devices. By storing the same data in multiple magnetic disk devices, it is possible to improve the reliability of the data and speed up the data reading. I was there.

[0003]

However, in the above-described conventional duplication processing of the magnetic disk device, when writing data, the same data is written in another magnetic disk device, and when the data cannot be read normally, To execute the process of reading data from another magnetic disk device and writing it as repair data,
Since the intervention of the OS is required, there is a drawback that the processing time increases as a whole system.

Further, since data transfer between the magnetic disk devices for duplication is performed through an interface used for normal data transfer, normal data transfer cannot be performed during that time. That is, there is a drawback that the time required for data transfer becomes long.

[0005]

SUMMARY OF THE INVENTION The present invention is a magnetic disk controller for connecting to a plurality of magnetic disk devices having dual ports to perform data duplication processing, the first of the plurality of magnetic disk devices. A first interface for writing and reading data to and from a port, and a second interface for writing and reading the same data as the data to and from second ports of the plurality of magnetic disk devices, The data read from the plurality of magnetic disk devices via the first and second interfaces is collated, and when the data read via the first interface has an error, the data is restored via the second interface. And a control unit.

[0006]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an information processing system for realizing an embodiment of the present invention. As shown in FIG. 1, this information processing system includes a magnetic disk controller (DKC) 300 and a magnetic disk controller 300.
A central processing unit (CPU) 100 for issuing data read / write commands to a main memory unit (MEM) 200
And a common bus 400 used for each data transfer
It is comprised including. Then, the control unit 1 of the magnetic disk control device 300 passes the interface 10 or the interface 20 to the magnetic disk device (DKU).
2 and the magnetic disk device 3 are used to transfer data and control operations associated therewith. Here, the interface 10 is used for normal data transfer, and the interface 2
0 is used for data transfer for duplicating the magnetic disk device.

In the present embodiment, the interface 10 and the interface 20 are provided to facilitate understanding of the description.
There are two magnetic disk devices connected to the magnetic disk device 2 and the magnetic disk device 3, and the others are omitted.

Next, the operation of this embodiment thus constructed will be described.

First, the write processing will be described.
When the write command is issued from the central processing unit 100, the magnetic disk control device 300 executes a seek command to the magnetic disk device 2 by the control unit 1 of the magnetic disk control device 300, so that the common bus 400 and the interface 10 are connected. Data is transferred to and from the main storage device 200 via.

Further, in parallel with the data transfer via the interface 10, the control unit 1 uses the interface 20 to transfer data to and from the magnetic disk device 3, and the data written in the magnetic disk device 2 is transferred. The same data as is written in the magnetic disk device 3. After the writing is completed, the magnetic disk control device 300 reports the operation end to the central processing unit 100 via the common bus 400.

Next, the reading process will be described.
When the read command is issued from the central processing unit 100, the magnetic disk control device 300 executes a seek command to the magnetic disk device 2 by the control unit 1, and executes the read operation after the seek operation of the magnetic disk device 2 is completed. Then, the data is transferred to and from the main storage device 200 via the common bus 400 and the interface 10.

In the read operation, if the data in the magnetic disk device 2 cannot be read normally, the control unit 1
Is the magnetic disk device 3 via the interface 20.
Data is read from the magnetic disk device 3 and the data is transferred from the magnetic disk device 3 via the interface 20 to the magnetic disk control device 300. Then, after the read operation is completed, the magnetic disk control device 300 reports the operation end to the central processing unit 100 via the common bus 400.

Subsequently, the control unit 1 uses the data read from the magnetic disk device 3 by using the interface 20 in parallel with the report of the end of the operation of the magnetic disk control device 300, and cannot read normally. The data of the magnetic disk device 2 is restored so that it can be read correctly. The magnetic disk control device 300 is the central processing unit 1
After the read / write operation of all data by the command issued from 00 is completed and the operation completion is reported to the central processing unit 100 via the common bus 400, the next processing from the central processing unit 100 is performed. Accept orders.

[0015]

As described above, the magnetic disk control device of the present invention writes the written data to another magnetic disk device or reads data from another magnetic disk device after the reading / writing of the data portion is completed. Since there is no need for the OS to intervene in the processing required for the duplication of the magnetic disk device, such as reading and writing the data as data for repair, there is an effect that the processing capacity of the entire system is improved.

Further, since the data transfer between the magnetic disk devices for the duplication processing is performed not by the interface used for the normal data transfer but by another dedicated interface, the normal data transfer can be performed during that time. Execution becomes possible and there is an effect that normal data transfer can be completed in a short time.

[Brief description of drawings]

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

[Explanation of symbols]

 1 Control Unit 2, 3 Magnetic Disk Unit (DKU) 10, 20 Interface 100 Central Processing Unit (CPU) 200 Main Memory Unit (MEM) 300 Magnetic Disk Controller (DKC) 400 Common Bus

Claims (1)

[Claims] 1. A magnetic disk control device for connecting to a plurality of magnetic disk devices having dual ports to perform data duplication processing, and writing data to and from a first port of the plurality of magnetic disk devices. And a first interface for reading and writing, and a second interface for writing and reading the same data as the data between the second ports of the plurality of magnetic disk devices, and the first and second interfaces A control unit for collating the data read from the plurality of magnetic disk devices via the second interface and repairing the data read via the first interface if there is an error. And a magnetic disk controller.