JPH08263221A - Redundant magnetic disk unit - Google Patents

Abstract

(57) [Summary] [Purpose] To autonomously copy data between magnetic disk devices in a duplicated magnetic disk device. [Structure] Two magnetic disk devices 9 and 11 and a magnetic disk controller 3 constitute a dual magnetic disk device.
The internal control unit 14 of the magnetic disk control unit 3 uses the host device 1
The copy instruction sent from the device is analyzed, and the 0-system device control unit 15 is made to read the data from the 0-system magnetic disk device 9 to the 0-system buffer memory 16. Then, through the device control units 15 and 18 of both systems, the 0 system buffer memory 1
Data is transferred from 6 to the 1-system buffer memory 19, and after the transfer is completed, the 1-system device control unit 18 is caused to write the data transferred to the 1-system buffer memory 19 to the 1-system magnetic disk device 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual magnetic disk device in which two magnetic disk devices are dualized.

[0002]

2. Description of the Related Art Conventionally, as a file storage device in a telephone exchange, for example, two magnetic disk devices are used in duplicate to improve the reliability of file storage.

Further, as a technique for controlling such a duplicated magnetic disc device in which two magnetic disc devices are duplicated, for example, a technique described in Japanese Patent Laid-Open No. 55-34756 is known.

In this technique, as shown in FIG. 6, a magnetic disk control unit 3 for controlling two magnetic disk devices 9 and 11 is provided, and this magnetic disk control unit 3 is used as a host device 1.
In response to one write command (command) received from the host device 3 via the interface unit 4, the data received from the host device 3 via the interface unit 4 and temporarily stored in the buffer memory 6 are stored in two different units. Magnetic disk device 9,
The write control units 8 and 10 are used to write the data in the same area 11. Further, the write end determination unit 5 issues a single write end report to the higher-level device when both the write control units 8 and 10 write to the two disks are completed. By doing so, the higher-level device 1 can perform double writing to two magnetic disk devices, as in the case of writing only to one magnetic disk device. The buffer control unit 7 in FIG. 6 controls the reading of data from the buffer memory 6 in response to a request from the write control units 8 and 10.

[0005]

The problem to be solved by the invention is shown in FIG.
According to the technique described in Japanese Patent Laid-Open No. 5-34756, in response to a single write command from a higher-level device, the magnetic disk control unit 3 autonomously writes the same data to two different magnetic disk devices in duplicate. Therefore, it is possible to reduce the processing load of the software or the like of the higher-level device 3.

However, when the data of one magnetic disk device is copied to the other magnetic disk device, or when the data of two magnetic disk devices is compared (data collation), etc. The host device 1 needs to individually control each magnetic disk device. For example, when copying the data of one magnetic disk device to the other magnetic disk device, the copy source magnetic disk device is controlled to read the data of this magnetic disk device once into the host device, and then It is necessary to control the copy destination magnetic disk device to write this data to this magnetic disk device. Further, in the case of performing data comparison of two magnetic disk devices, each magnetic disk device is individually controlled, the data of each magnetic disk device is read into the host device, and both are collated in the host device. There is a need.

In other words, when various processes such as copying and comparing data are to be realized between the duplicated magnetic disk devices, the load on the host device is not reduced.
The processing efficiency of the host device is reduced. Further, the traffic of the processor bus used for transferring data and commands between the host device and the duplicated magnetic disk device will increase. Then, for example, when the processor bus is also used for data transfer between other devices and there is no traffic margin, the traffic of the processor bus due to the data transfer between the higher-level device and the duplicated magnetic disk device. Therefore, the overall processing efficiency will be reduced due to the increase of.

Therefore, an object of the present invention is to provide a dual magnetic disk device capable of autonomously performing data processing between two magnetic disk devices.

[0009]

[Means for Solving the Problems] To achieve the above object,
The present invention is, for example, a two-system magnetic disk device, and a magnetic disk control unit that is connected to a host device and the two-system magnetic disk device, respectively, and controls the two-system magnetic disk device according to instructions from the host device. A dual magnetic disk drive, wherein the magnetic disk control unit controls the magnetic disk drive of a corresponding system provided corresponding to each system of the two systems of magnetic disk drives. System, and an internal control unit for controlling each of the two systems of magnetic disk control systems in accordance with an instruction from the host device, and each magnetic disk control system stores data to be written in the corresponding system magnetic disk device. A buffer memory that temporarily stores the data read from the magnetic disk device of the corresponding system and that is stored in the buffer memory. Has a device control unit for controlling reading data from the magnetic disk device of the system to the buffer memory corresponding to the corresponding write to the magnetic disk device of the system data, the internal control unit, the 2
Provided is a dual magnetic disk device characterized by having a transfer means for transferring data between two buffer memories of a magnetic disk control system of the system.

[0010]

According to the above-mentioned dual magnetic disk device, for example, the internal control unit corresponds to the device control unit of the magnetic disk control system of one of the two systems of magnetic disk control systems. Data is read from the device into a buffer memory of the same magnetic disk control system as the device control unit, and the data read by the transfer means into the buffer memory of the one magnetic disk control system is read from the other magnetic disk control system. The data is transferred to the buffer memory, and the device control unit of the other magnetic disk control system transfers the data transferred by the transfer unit to the buffer memory of the same magnetic disk control system as the device control unit. By writing to the disk device, the data between two magnetic disk devices can be copied. - and it can be autonomously performed on dual magnetic disk device.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the dual magnetic disk drive according to the present invention will be described below.

FIG. 1 shows the configuration of a dual magnetic disk drive according to this embodiment.

As shown in the figure, the duplicated magnetic disk device according to this embodiment comprises a magnetic disk controller 3 connected to a host device 1 via a processor bus 2 and two systems of magnetic disk devices 9 and 11. .

Further, as shown in the figure, the magnetic disk control unit 3 includes a processor bus interface unit 12 for controlling input / output with the processor bus 2 and an internal control unit 14.
And an internal processor bus 13. Further, corresponding to the two systems of magnetic disk devices 9 and 11, buffer memories 16 and 19 for both writing and reading, device control units 15 and 18, and magnetic disk device bus control units 17 and 2 are provided.
It has two 0s. In each system, the device control units 15 and 18 control the reading and writing of data of the magnetic disk devices 9 and 11 under the control of the internal control unit 14 via the magnetic disk device bus control units 17 and 20, respectively. To do. The magnetic disk device bus control units 17 and 20 are bus interfaces adopted by a bus to which the magnetic disk devices 9 and 11 are connected, for example, SCSI (Small Computer System Inte).
rface) to control input / output to / from the bus, and relay data and commands between the magnetic disk devices 9 and 11 and the device control units 15 and 18. Buffer memory 1
Reference numerals 6 and 19 denote data written to the magnetic disk devices 9 and 11 by the device control units 15 and 18, and the device control unit 1.
Numerals 5 and 18 are buffer memories for temporarily storing the data read from the magnetic disk devices 9 and 11.

In this embodiment, with such a configuration, the copy operation of reading the data of one magnetic disk device and writing it in the other magnetic disk device, and the data of both magnetic disk devices 9 and 11 are copied. -The various functions of the dual magnetic disk device, such as a compare operation for simultaneously reading and verifying the data, are performed without going through the host device 1. Further, the buffer memory is configured to be used for both writing and reading, so that data transfer between the buffer memories can be minimized.

In the present embodiment, the magnetic disk controller 3 autonomously performs the following three processes as data processing between two magnetic disks.

(1) Copy: Copy the data of one magnetic disk device to the other magnetic disk device.

(2) Compare: The data of both magnetic disk devices is read and the data is compared.

(3) Verify: In order to improve the reliability of the write data of the magnetic disk device, at the time of writing to both systems, the data is read immediately after writing to both systems and the contents of both buffer memories are collated to verify the data. Check the normality of. In the case of single-system writing, the normality of the data is confirmed by reading the data of that system immediately after the single-system writing and collating it with the contents of the buffer memory of the non-written system.

The operation for realizing each process will be described below.

In the following description, the system of the magnetic disk device 9, the buffer memory 16, the device control unit 15, and the magnetic disk device bus control unit 17 will be referred to as system 0, the magnetic disk device 11, the buffer memory 19, and the device control. Part 1
8. The system of the magnetic disk device bus control unit 20 will be referred to as 1 system.

First, the copy process will be described with reference to FIG. 2 (here, the case of copying data from the 0-system magnetic disk device 9 to the 1-system magnetic disk device 11 will be described).

In this process, first, a copy instruction (command issuance) sent from the host device 1 via the processor bus 2 and the processor bus interface unit 12 is received.
The internal control unit 14 analyzes this instruction and operates as follows.

That is, the 0-system device controller 15 is controlled to read the data from the 0-system magnetic disk device 9 to the 0-system buffer memory 16. Then, the data is transferred from the 0-system buffer memory 16 to the 1-system buffer memory 19 via the device control units 15 and 18 of both systems. After the transfer is completed, the 1-system device control unit 18 causes the 1-system magnetic disk device 11 to write the transferred data to the 1-system buffer memory 19.

After these operations are completed, the internal control unit 14 reports the completion of the copy instruction to the higher-level device 1 through the processor interface unit 12 based on the status information and the like.

Next, the compare process will be described with reference to FIG.

In this process, first, the internal control unit 14, which receives a compare instruction (command issuance) sent from the host device 1 via the processor bus 2 and the processor bus interface unit 12, analyzes this instruction. , Works as follows:

That is, the 0-system device control unit 15 is caused to read data from the 0-system magnetic disk device 9 to the 0-system buffer memory 16 and at the same time, the 1-system device control unit 18 is read from the 1-system magnetic disk device 11 to 1. System buffer memory 19
Read the data.

After completion of the reading, the contents of the buffer memories 16 and 19 are read out to the internal control unit 14 via the device control units 15 and 18 of both systems, collated with each other, and the processor bus interface unit is read. The result of the collation is reported to the upper level device 1 via 12 via the status information or the like in response to the compare instruction.

Next, the verify process at the time of writing in both systems will be described with reference to FIG.

In this process, first, the internal control unit 14, which receives the write-instruction-with-verify write command (command issuance) sent from the host device 1 via the processor bus 2 and the processor bus interface unit 12, Parse the instructions,
It works as follows.

That is, the processor bus interface
The write data sent from the higher-level device 1 via the processor bus 2 captured by the processor bus interface unit 12 to the interface unit 12 is transferred to the device control units 15 and 1 of both systems.
8 to store them in the buffer memories 16 and 19 of both systems.

Then, the device control units 15 and 1 of both systems
The data stored in the buffer memories 16 and 19 are written in parallel to the magnetic disk devices 9 and 11 of both systems. Then, after the writing of the magnetic disk devices 9 and 11 is completed, the magnetic disk devices 9 and 1 of both systems are
1 stores data in the same area of both systems, which has been instructed to write by the magnetic disk devices 9 and 11, in the buffer memory 1 of each.
Make 6 and 19 read.

After the reading is completed, the internal control unit 14
Then, the contents of the buffer memories 16 and 19 are read out through the device control units 15 and 18 of both systems, and these are collated,
Through the processor bus interface section 12, the result of the collation is reported to the upper-level device 1 by the status information or the like for the write instruction with both systems with verification.

Next, the verify process at the time of one-sided writing will be described with reference to FIG.

In this process, first, the internal control unit 14 which receives the verifying one-sided write instruction (command issuance) sent from the higher-level device 1 via the processor bus 2 and the processor bus interface unit 12, This instruction is analyzed and it operates as follows. Here, it is assumed that the instruction sent from the higher-level device 1 is a verify-attached one-system write instruction to the 0-system.

That is, the processor bus interface
The write data sent from the higher-level device 1 via the processor bus 2 captured by the processor bus interface unit 12 to the interface unit 12 is transferred to the device control units 15 and 1 of both systems.
8 to store them in the buffer memories 16 and 19 of both systems. Then, the 0-system device control unit 15 instructed by the higher-level device 1 writes the data stored in the 0-system buffer memory 16 into the 0-system magnetic disk device 9. After the writing of the 0-system magnetic disk device 9, the 0-system device controller 15 is made to read the data instructed by the 0-system magnetic disk device 9 into the 0-system buffer memory 16. .

After the reading is completed, the internal control unit 14
Then, the contents of the buffer memories 16 and 19 are read out through the device control units 15 and 18 of both systems, and these are collated,
Through the processor bus interface unit 12, the host device 1 is informed of the result of the collation and the completion report for the verifying one-sided write instruction by the status information or the like.

That is, in the case of the verify process at the time of one-sided writing, the data written in the buffer memory of the system in which there is no writing in the magnetic disk device is actually once written in the magnetic disk device and then the buffer is written. The data will be collated with the data read in the memory.

As described above, according to this embodiment, in the duplicated magnetic disk device, it is possible to independently control the data transfer of the magnetic disk devices of the two systems. Various operations such as copy, compare and verify using the magnetic disk device of the system can be autonomously realized, the processing load of the software of the host device can be reduced, and the processor bus usage efficiency can be improved. be able to.

[0041]

As described above, according to the present invention, it is possible to provide a dual magnetic disk device capable of autonomously performing data processing between two magnetic disk devices.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a dual magnetic disk drive according to an embodiment of the present invention.

FIG. 2 is a diagram showing a copy process of the dual magnetic disk drive according to the embodiment of the present invention.

FIG. 3 is a diagram showing a compare process of the dual magnetic disk drive according to the embodiment of the present invention.

FIG. 4 is a diagram showing a verify process at the time of both-system writing of the dual magnetic disk drive according to the embodiment of the present invention.

FIG. 5 is a diagram showing a verify process at the time of single-sided writing of the dual magnetic disk drive according to the embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a conventional dual magnetic disk device.

[Explanation of symbols]

 1 ... Higher-order device 2 ... Processor bus 3 ... Magnetic disk control unit 4 ... Interface unit 5 ... Write end determination unit 6 ... Buffer memory 7 ... ... Buffer control unit 8 ... 0 system write control unit 9 ... 0 system magnetic disk device 10 ... 1 system write control unit 11 ... 1 system magnetic disk device 12 ...・ Processor bus interface unit 13 ・ ・ ・ Internal processor bus 14 ・ ・ ・ ・ Internal control unit 15 ・ ・ ・ ・ 0 system device control unit 16 ・ ・ ・ ・ ・ ・ 0 system buffer memory 17 ・ ・ ・ ・ ・ ・ 0 system magnetism Disk device bus control unit 18 ... 1 system device control unit 19 ... 1 system buffer memory 20 ... 1 system magnetic disk device bus control unit

Claims (6)

[Claims] 1. A two-system magnetic disk device, and a magnetic disk control unit which is connected to a host device and the two-system magnetic disk device, respectively, and controls the two-system magnetic disk device in accordance with instructions from the host device. A dual magnetic disk drive system, wherein the magnetic disk control unit controls two magnetic disk devices of two systems, which are provided corresponding to each system of the two magnetic disk devices. And an internal control unit for controlling each of the magnetic disk control systems of the two systems in accordance with an instruction from the host device, and each magnetic disk control system temporarily writes data to be written to the magnetic disk device of the corresponding system. The buffer memory that stores and temporarily stores the data read from the magnetic disk device of the corresponding system, and the data stored in the buffer memory. Of the magnetic disk device of the corresponding system, and a device control unit for controlling reading of data from the magnetic disk device of the corresponding system to the buffer memory, wherein the internal control unit includes the magnetic disk of the two systems. A dual magnetic disk device comprising a transfer means for transferring data between two buffer memories of a control system. 2. A two-system magnetic disk device, and a magnetic disk control unit which is connected to a host device and the two-system magnetic disk device, respectively, and controls the two-system magnetic disk device in accordance with instructions from the host device. A dual magnetic disk drive system, wherein the magnetic disk control unit controls two magnetic disk devices of two systems, which are provided corresponding to each system of the two magnetic disk devices. And an internal control unit for controlling each of the magnetic disk control systems of the two systems in accordance with an instruction from the host device, and each magnetic disk control system temporarily writes data to be written to the magnetic disk device of the corresponding system. The buffer memory that stores and temporarily stores the data read from the magnetic disk device of the corresponding system, and the data stored in the buffer memory. Of the magnetic disk device of the corresponding system, and a device control unit for controlling reading of data from the magnetic disk device of the corresponding system to the buffer memory, wherein the internal control unit includes the magnetic disk of the two systems. A duplicated magnetic disk device comprising a collating means for collating data stored in two buffer memories of a control system. 3. The dual magnetic disk device according to claim 1, wherein the internal control unit is one of the two magnetic disk control systems in response to an instruction from the host device. Of the magnetic disk device of the corresponding system to read the data into the buffer memory of the same magnetic disk control system as the device control unit, and the transfer means reads the data into the buffer memory of the one magnetic disk control system. The transferred data is transferred to the buffer memory of the other magnetic disk control system, and the device control unit of the other magnetic disk control system is transferred to the same buffer memory of the magnetic disk control system as the device control unit. Duplication characterized by causing the data transferred by the means to be written to the magnetic disk device of the corresponding system Magnetic disk drive. 4. The dual magnetic disk drive according to claim 2, wherein the internal control unit is configured to operate in parallel with two device control units of the two magnetic disk control systems in accordance with an instruction from the host device. Then, the data of the magnetic disk device of the corresponding system is read into the same buffer memory of the magnetic disk control system as the device control unit, and stored in the two buffer memories of the two systems of magnetic disk control system by the collating means. A duplicated magnetic disk device for collating the stored data and reporting the collation result to the higher-level device. 5. The duplicated magnetic disk device according to claim 2, wherein the internal control unit is provided in two buffer memories of the two systems of magnetic disk control systems in accordance with an instruction from the host device. Each of the data sent from
In the two device control units of the system magnetic disk control system,
At the same time, the data stored in the buffer memory of the same magnetic disk control system as the device control unit is written to the magnetic disk device of the corresponding system, and the written data is controlled by the magnetic disk device of the corresponding system. Part to be read into the same buffer memory of the magnetic disk control system as that of the unit, and the verification means verifies the data stored in the two buffer memories of the magnetic disk control system of the two systems, and reports the verification result to the host device. A dual magnetic disk drive characterized by the following. 6. The dual magnetic disk drive according to claim 2, wherein the internal control unit is provided in two buffer memories of the two magnetic disk control systems in response to an instruction from the higher-level device. Each of the data sent from
Write the data stored in the buffer memory of the same magnetic disk control system as the device control unit to the magnetic disk device of the corresponding system only to the device control unit of one of the magnetic disk control systems of the system In addition, the written data is read from the corresponding magnetic disk device into the buffer memory of the same magnetic disk control system as the device control unit, and the two buffer memories of the two magnetic disk control systems are used by the collating means. A duplicated magnetic disk device characterized by collating the data stored in, and reporting the collation result to the host device.