Hot stand-by method and computer system for implementing hot stand-by method

摘要

The computer system provides a processing unit and normal-use and stand-by main storage units, pre-loads an application program and a control program required for executing the application program in both of the main storage units, in a normal operating time, functions the normal- use main storage unit only as the main storage under the control of the processing unit, executes the control program and the application program stored in the normal-use main storage unit, in a software-fault occurring time, functions the stand-by main storage unit only as the main storage unit under the control of the processing unit, and executes the control program and the application program stored in the stand-by main storage unit. Then, a recovery program contained in the application program stored in the stand-by main storage unit serves to recover the state of the application program into the state before fault occurs. Next, the application program is kept being executed or re-started from the head of the application program.