JPH0528057A - File backup circuit - Google Patents

Abstract

PURPOSE:To make a file dual without degrading the processing capability of a CPU on the main body side. CONSTITUTION:An external storage write part 11 of a main body CPU 1 writes data transferred from an application program in a shared memory area 12a virtually mapped in a shared memory 22 of a control board 2 for the purpose of preserving this data in an external storage 3. Data written in the shared memory area 12a is written in the shared memory 22. The external storage write part 11 uses a DMA control part 13 to write data of the shared memory area 12a in the external storage 3 and sends an interrupt report to a copy control part 21 of the control board 2. When receiving the interrupt report, the copy control part 21 starts a copy program to write data of the shared memory 22 in an external storage 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file backup circuit, and more particularly to file duplication in a method of storing and managing files in an external storage medium.

[0002]

2. Description of the Related Art Conventionally, in this type of file management system, as shown in FIG. 3, in order to duplicate a file, the data of the file is stored in an external magnetic disk 6 by a main CPU (central processing unit) 5. After writing (step 51 in FIG. 3), the same data is written in another magnetic disk 7 (step 52 in FIG. 3).

Further, after the data of the file is written to the magnetic disk 6 by the main body CPU 5, the data of the file is copied to another file by the background processing by using the free time of the main body CPU 5 to duplicate the file. Is going.

In such a conventional file management system,
When writing the same data to another magnetic disk 7 after writing the file data to the magnetic disk 6 by the main body CPU 5, the data writing to the magnetic disks 6 and 7 is continuously performed using the main body CPU 5. Therefore, there is a drawback that the performance of the entire system is deteriorated when writing to the file becomes frequent.

Further, when the data of the file is written to the magnetic disk 6 by the main body CPU 5 and then the data of the file is copied to another file by the background processing using the free time of the main body CPU 5,
However, if the copy source file is destroyed while the backup file has not been written yet, the information of the file in the meantime will be erased, resulting in a problem of reliability.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned drawbacks of the conventional ones, and provides a file backup circuit capable of duplicating a file without lowering the processing capacity of the CPU of the main body. For the purpose of provision.

[0007]

The file backup circuit according to the present invention is a file backup circuit for duplicating a file by writing the data stored in the buffer in the central processing unit to the first and second external storage devices. Storage means for storing the data in the buffer at the same time as storing the data in the buffer, and the storage means for writing the data from the buffer to the first external storage device. A control board including a control means for controlling to write the stored data in the second external storage device is connected to the central processing unit.

[0008]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention, and FIG. 2 is a conceptual diagram showing an embodiment of the present invention. In these figures, the main body CPU 1 and the control board 2 are connected by bus connection, and are connected to the external memories 3 and 4, respectively. Further, the shared memory area 12 a of the memory 12 of the main body CPU 1 is virtually mapped to the shared memory 22 of the control board 2. Normally, the main body CPU 1 has a file in the external storage 3 and reads / writes the file.

An application program (AP) 15 operating in the main body CPU 1 transfers data to an external storage writing unit (driver) 11 via an operating system 14. The external storage writing unit 11 writes the transferred data in the shared memory area 12a virtually mapped to the shared memory 22 of the control board 2 in order to save the transferred data in the external storage 3. At this time, the data and address from the external storage writing unit 11 to the shared memory area 12a are sent to the control board 2 and the data is written in the shared memory 22.

After that, the external memory writing unit 11 executes the DMA
(Direct memory access) The control is passed to the control unit 13, the data of the shared memory area 12a is started to be written to the external storage 3 by using the DMA, and the interrupt notification is sent to the copy control unit 21 of the control board 2. Upon receiving the interrupt notification, the copy control unit 21 activates the copy program,
The writing process of the data on the shared memory 22 to the external storage 4 is performed. Here, the copy control unit 21 is a CPU for operating a copy program.

The external storage writing unit 11 writes the data in the shared memory area 12a to the external storage 3 by the DMA control unit 13 without knowing that the writing process to the external storage 4 is being performed, and the process is completed. At that time, the completion notification is sent to the application program 15 via the operating system 14.

As a result, the data from the application program 15 is written in the external storages 3 and 4, and the same files are created in the external storages 3 and 4, respectively. Therefore,
Only by writing data from the main body CPU 1 to the external storage 3, the files can be duplicated using the external storages 3 and 4. Application program 1
The data from 6 can be duplicated in the same manner as above.

In this way, when the files are duplicated, the shared memory area 1 in which the data to the external storage 3 is virtually mapped to the shared memory 22 of the control board 2
2a and then writing to the external storage 3 by the DMA control unit 13 and sending an interrupt notification to the copy control unit 21 of the control board 2 so that the data written in the shared memory area 12a on the shared memory 22 and By writing the same data in the external storage 4, the files in the external storage 3 can be backed up under the control of the copy control unit 21 on the control board 2.
Therefore, the files can be duplicated in the external storages 3 and 4 without lowering the processing capacity of the main body CPU 1.

Further, since the files are not backed up in the background processing by using the free time of the main body CPU1, the load of the main body CPU1 can be reduced, and even if the copy source file is destroyed, the external storage is possible. The file can be stored in No. 4, and there is no problem in reliability.

[0016]

As described above, according to the present invention, when the data stored in the buffer in the central processing unit is written into the first and second external storage devices to duplicate the file, When writing data from the buffer to the first external storage device, the data is stored in the storage means having the same address as the buffer, and the data stored in the storage means is written in the second external storage device. By controlling with the control means, there is an effect that the files can be duplicated without reducing the processing capacity of the central processing unit on the main body side.

[Brief description of drawings]

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

FIG. 2 is a conceptual diagram showing an embodiment of the present invention.

FIG. 3 is a conceptual diagram showing a conventional example.

[Explanation of symbols]

 1 Main CPU 2 Control board 3, 4 External storage 11 External storage writing unit 12 Memory 12a Shared memory area 13 DMA control unit 21 Copy control unit 22 Shared memory

Claims (1)

Claim: What is claimed is: 1. A file backup circuit for duplicating a file by writing data stored in a buffer in a central processing unit to a first and a second external storage device. Storage means having the same address as the buffer and storing the data in the buffer at the same time as storing the data in the buffer; and storing the data in the storage means at the time of writing the data from the buffer to the first external storage device. A file backup circuit, wherein a control board including a control means for controlling writing of the data to the second external storage device is connected to the central processing unit.