JPH02253345A - Input/output controller - Google Patents

Abstract

PURPOSE:To attain a redundant system applying a hot stand-by system by performing the actual input/output control to one of two CPUs of a double system of a redundant structure and emulating the input/output control to the other CPU respectively. CONSTITUTION:An input/output control part 2 includes a means which performs the input/output control to a fixed disk device 3 against an input/output request of one of CPU 11 and 12 of a double system and emulates the input/output control against the input/output request of the other CPU. That is, the device 3 is controlled and a designated process is carried out to the input/output request received from the CPU 11 of a 0 system. Then the process history and data are stored in the part 2. On the other hand, the control of the device 3 is emulated based on the information to the input/output request given from the CPU 12 of a 1 system. Then the real control is not carried out to the device 3. As a result, both CPUs of a double system can be actuated in parallel to each other. Then a redundant system is attained with use of a hot stand-by system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is applied to an input/output control device for an electronic computer system in which the central processing unit is a redundant dual system.

〔overview〕

The present invention provides an input/output control device that performs actual input/output control on one side of a dual system central processing unit with a redundant structure and emulates input/output control on the other. The central processing unit can operate in parallel, and a redundant system using a hot standby system can be realized.

[Conventional technology]

With conventional input/output control devices, when there is a single input/output device, it is impossible to process both input/output requests due to the dual system central processing unit.1. A standby system was used.

[Problem that the invention seeks to solve]

However, since such conventional input/output control devices employ a cold standby method, they have the disadvantage that it takes time to recover from a failure.

The present invention solves the above-mentioned drawbacks, and aims to provide an input/output control device that can implement a hot standby redundancy system.

[Means for solving problems]

The present invention provides a redundant dual-system central processing unit, a single input/output device for inputting and outputting data between the dual-system central processing unit, and the dual-system central processing unit. In the input/output control device, the input/output control unit includes an input/output control unit that performs input/output control with the single input/output device based on input/output requests from the dual-system central processing unit. The present invention is characterized in that it includes means for performing input/output control with the single input/output device for one input/output request, and emulating input/output control for the other input/output request.

Here, "emulate" means to execute the same program and obtain the same result.

[Effect]

The input/output control unit performs actual input/output control with a single input/output device in response to input/output requests from one side of the dual system central processing unit, and performs input/output control in response to input/output requests from the other side. to emulate. This operation enables parallel operation of dual-system central processing units and realizes a redundant system using a hot standby system. Therefore, the time from failure occurrence to recovery can be shortened.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings. 1st
The figure is a block diagram of an input/output control device according to an embodiment of the present invention. In FIG. 1, the input/output control device includes a Q-system central processing unit 1 and an I-system central processing unit 1□ as redundant dual-system central processing units, and a dual-system central processing unit 1IS12. The fixed disk device 3 is used as a single input/output device that inputs and outputs data between the two, and the input/output control with the fixed disk device 3 is performed based on the input/output requests of the dual system central processing unit 11 and 12. and an input/output control unit 2 that performs the following operations.

Here, the feature of the present invention is that the input/output control unit 2 includes a dual system central processing unit 1. ．． 12, performs input/output control with the fixed disk device 3,
For the other input/output request, it includes means for emulating input/output control.

The operation of the input/output control device having such a configuration will be explained. In response to an input/output request from the 0-system central processing unit 11, the fixed disk device 3 is controlled as usual to perform the specified processing. At this time, the 1-system central processing unit 12 stores the processing history and data in the input/output control unit 2.
In response to an input/output request from , the control of the fixed disk device 3 is emulated based on the above information, and actual control of the fixed disk device 3 is not performed. During operation of this device, the clock signal of the central processing unit 12 of the 1-system is set slightly slower than that of the 0-system so that input/output requests from the 0-system central processing unit II always precede input/output requests from the 1-system. I'll keep it.

FIG. 2 is a block diagram of the input/output control device of the present invention. In FIG. 2, 21 is a microprocessor, 22
is ROM, 23 is RAM, 24 is O-system central processing unit 1
1 is an interface unit, and 25 is an l-based central processing unit 12.
26 is a fixed disk controller, and 27 is a peripheral LSI. microprocessor 2
1 controls the fixed disk controller 26 according to firmware installed in the ROM 22, and controls the fixed disk device 3. RAM M23 and peripheral LSI2
7 supports the execution of the microprocessor 21. 0 system central processing unit 1. When processing an input/output request from, the processing history and data are stored in the RAM 23. Central processing unit 15.1. The interface unit 24,25 with each central processing unit 1. ．． Receives commands from 12 and returns status.

The table shows the contents of the RAM of the input/output control device of the present invention, and shows the processing history and data stored in the RAM 23 when processing an input/output request from the 0-system central processing unit 11. Generally, multiple commands such as a head movement command and a read command are issued to the fixed disk controller in response to one input/output request. Depending on the type of commands issued to the fixed disk controller, there are some that involve data transfer and others that do not. 0 system central processing unit 1. When processing an input/output request from, an input/output request command, a command issued to the fixed disk controller 26 when executing the command,
The transferred data, the status response from the fixed disk controller 26, and the status returned to the central processing unit 1 at the end of processing are stored in the RAM 23.

(Hereinafter, in the margin of this page) [Effects of the Invention] As explained above, the present invention has the excellent effect of enabling parallel operation of both CPUs and realizing a redundancy system using a hot standby system.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an input/output control device according to an embodiment of the present invention. FIG. 2 is a block diagram of the input/output control section of the input/output control device of the present invention. 11...0-system central processing unit, 1□...1-system central processing unit, 2...I/O control unit, 3...fixed disk device, 21...microprocessor, 22...・R
OM, 23...RAM, 24.25...Interface section, 26...Fixed disk controller, 27
...Peripheral LSI. 1st embodiment diagram

Claims (1)

[Scope of Claims] 1. A dual-system central processing unit with a redundant configuration; a single input/output device that inputs and outputs data between the dual-system central processing unit; an input/output control unit that performs input/output control with the single input/output device based on input/output requests from the central processing unit, the input/output control unit comprising: means for performing input/output control with the single input/output device for one input/output request of the central processing unit, and emulating input/output control for the other input/output request. Characteristic input/output control device.