METHOD FOR JUDGING ABNORMALITY OF BACKUP DATA AND METHOD FOR PROCESSING ABNORMALITY AT ABNORMALITY TIME

摘要

PURPOSE: To provide an abnormality judging method for backup data and an abnormality processing method for abnormality time which can judge which of control data and check data is abnormal by collating them with each other and can repair the abnormal data. CONSTITUTION: Data 1 is collated with mirror data 1A and mirror data 1B respectively and if the discrepancy of the data contents is detected through one of the collating processes, it is judged that the backup data is abnormal, so that the data decided as abnormal data by majority decision making is repaired. Specially, when the discrepancy of the data contents is detected in both the collating processes, it is judged that the data 1 is abnormal. In this case, it is judged whether or not the mirror data 1A and mirror data match with each other and when both the data match each other, it is judged that only the data 1 is abnormal, thereby copying the data contents of the mirror data 1A to the data 1 according to a majority decision.