INFORMATION PROCESSING SYSTEM

PURPOSE:To continue a job as long as possible by delaying an alarm to a user and the start of shut-down processing such as the stopping processing of an application program. etc., to a point near to backup limitation by a no- break power unit by dynamically varying the capacity of disk cache memory by the no-break power unit corresponding to a time when backup can be performed. CONSTITUTION:A timer 6 starts subtraction processing on a register 7 replying to a trigger signal supplied from the no-break power unit 2 via an abnormality notification interface 11. Such subtraction processing is adjusted so as to be fitted in the battery discharge characteristic of the no-break power unit 2. An OS 3, after occurrence of power failure, dynamically varies the write data capacity of the disk cache memory 8 so as to complete prescribed processing normally within the time when the backup can be performed by monitoring the value of the register 7 periodically. When the write data capacity is decreased, data disabled to be stored in the disk cache memory 8 is written on a secondary memory device 5.