JPH02294723A - Duplex control method for auxiliary memory device - Google Patents

Abstract

PURPOSE:To secure the holding of the identity in the contents of duplexed auxiliary memory devices within the same time as a data writing time with one auxiliary memory device by writing/reading the data in/from either one of the duplexed devices and simultaneously wiring the writing data in the memory of the other auxiliary memory device, as well. CONSTITUTION:A processor 4 in a CPU 1 reads out/writes the data from/in the memories 5 in the auxiliary memory devices 2 through a duplex control part 7. Each of memory control parts 8, 9 reads out the data from the memory of its own auxiliary memory device, but writes the data simultaneously in the memory of the self-auxiliary memory device and the memory of the other device. Since the same data are written in both memories 5, 6 of the duplexed auxiliary memory devices 2, 3 within the same data writing time as the one used for the data writing time of one device, identity in the contents of the memories 5, 6 of the auxiliary memory devices 2, 3 can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a duplex control method for auxiliary storage devices.

[Conventional technology]

FIG. 2 is a configuration diagram of a conventional computer system disclosed in, for example, Japanese Patent Application Laid-Open No. 82-115555. In the figure, (1) is a central processing unit, (2) and (3) are auxiliary storage devices, (4) is a processor, (5) and (6) are memories, and (7) is a duplication control unit, and the processor (4) of the central processing unit (1) is a duplication control unit (7). Auxiliary storage (2) through (3) memory (5)
, (8).

(Problem to be Solved by the Invention) Since the conventional computer system is configured as described above, the processor of the central processing unit must write the same data to each of the duplicated auxiliary storage devices. Therefore, data writing time was twice as long as when there was only one auxiliary storage device.

This invention was made to solve the above-mentioned problems, and it is possible to maintain the sameness of the memory contents of a duplicated auxiliary storage device in the same amount of time as the data writing time of one auxiliary storage device. The present invention provides a method for controlling redundancy of an auxiliary storage device that can perform the following steps.

[Means to solve the problem]

The duplication control method for auxiliary storage devices according to this invention is such that in a computer system equipped with a duplexed auxiliary storage device that can be accessed from a central processing unit, the central processing unit It has a function to detect whether each device is abnormal or has recovered, and if an abnormality is detected in one of the dual auxiliary storage devices, access to that auxiliary storage device will be interrupted. Since then, the system has operated only with the other healthy auxiliary storage device, and when it detects that the abnormal auxiliary storage device has been restored, the contents of the other healthy auxiliary storage device are restored via the memory control unit. After the auxiliary storage device has been damaged, redundant operation of the auxiliary storage device will be resumed, and data writing and reading will be performed as described in 2 above.
A function in which data written to one auxiliary storage device is simultaneously written to the memory of the other auxiliary storage device via the memory control unit of the auxiliary storage device. It has the following.

[Effect]

In this invention, the central processing unit writes data and reads data in one of the auxiliary storage devices,
When the memory control unit of the auxiliary storage device receives write data from the central processing unit, it also transfers the data to the other auxiliary storage device, and simultaneously writes data to one auxiliary storage device and writes the data to the other auxiliary storage device. The same data is also written to the device, and the data N% when there is only one auxiliary storage device
Data is written to both memories of the duplicated auxiliary storage device in the same time as the write time.

〔Example〕

FIG. 1 is a block diagram of a computer system to which this invention is applied, in which (1) is a central processing unit, (2)
and (3) is an auxiliary storage device, (4) is a processor, (
5) and (6) are memories, (7) is a duplex control unit, (
8) and (9) indicate memory control units. The processor (4) of the central processing unit (1) controls the memory (5) of the auxiliary storage device (2) via the duplication control unit (7). The memory control units (8) and (9) read data from the memory of each auxiliary storage device, but write data from the memory of each auxiliary storage device as well as the other memory. This is also done simultaneously for the memory of the auxiliary storage device.

For example, if the auxiliary storage device (2) is currently used and the auxiliary storage device (3) is used as a backup, and now the central processing unit (1) writes data to the currently used auxiliary storage device (2), the current The memory control unit (8) in the auxiliary storage device (2) writes the write data from the central processing unit (1) to the memory (5) in its own device, and also writes the write data from the central processing unit (1) to the memory in the spare auxiliary storage device (3). The same data as above is also written in (6).

Next, the operation when a failure occurs in the auxiliary storage device (2) and when it recovers will be described below.

The failure of the auxiliary storage device (2) is caused by the failure of the central processing unit (1).
The processor (4) detects the
) will be notified. When a duplication control unit (7) detects a failure in the auxiliary storage device (2), the duplication control unit (7) controls the auxiliary storage device (2) or (3) for reading and writing data from the processor (4) to the auxiliary storage device (2) or (3). suspending access to the device (2);
Data is read and written to the auxiliary storage device (3).

When the auxiliary storage device (2) recovers from the failure, the duplication control unit (7) detects this and notifies the processor (4) to that effect. In response to the above notification, the processor (4) stores the memory (
Instructs to copy the contents of 6) to memory (5). Having received this instruction, the memory control unit (8) of the auxiliary storage device (2) copies the contents of the memory (δ) of the auxiliary storage device (3) to the memory (5) of its own device (2), and then duplicates the contents. Resume operation.

As explained above, in order to make the contents of the memories (5) and (6) of both the duplicated auxiliary storage devices (2) and (3) the same, the data written to one of the auxiliary storage devices is Since data is simultaneously written to the memory of the other auxiliary storage device by the memory control units (8) and (9), the data is written in the same time as when there is only one auxiliary storage device, making it redundant. Write data to both memories of the auxiliary storage device, auxiliary storage device (2),
The contents of memories (5) and (61) in (3) can be made the same.

〔Effect of the invention〕

As described above, according to the present invention, even if the auxiliary storage devices are duplicated, the memory control unit writes data to each memory at the same time, so data writing when there is only one auxiliary storage device is possible. Data can be written to both memories of the duplicated auxiliary storage device in the same time as the write time, and the contents of the memory of the auxiliary storage device can be kept identical.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a computer system according to this invention.
FIG. 2 is a block diagram of a conventional computer system. In the figure, (1) is the central processing unit, (2) and (3
) is an auxiliary storage device, (4) is a processor, (5) and (6) are memories, (7) is a duplication control section, and (8) and (9) are memory control sections. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa Figure 6. On August 29, 1999, the statement ``Contents'' on page 7, line 18 of the Specification of Contents of the Amendment is amended to read ``Contents''.

Claims (1)

[Claims] In a computer system equipped with duplicated auxiliary storage devices accessible from the central processing unit, the central processing unit has a function of detecting that each of the duplicated auxiliary storage devices is abnormal and has been restored. If an abnormality is detected in one of the duplicated auxiliary storage devices, access to that auxiliary storage device is interrupted, and the operation is continued using only the other healthy auxiliary storage device, and the abnormality is detected. When it is detected that the auxiliary storage device that was previously restored has been restored, the contents of the other healthy auxiliary storage device are copied to the recovered auxiliary storage device via the memory control unit, and then the contents of the auxiliary storage device 2 are restored.
The duplication operation is restarted, data is written and read to one of the duplexed auxiliary storage devices, and the data written in one auxiliary storage device is transferred to the other auxiliary storage device via the memory control unit of the auxiliary storage device. 1. A redundant control method for an auxiliary storage device, characterized by having a function of simultaneously writing data into the memory of the auxiliary storage device.