Access control method for shared duplex direct access storage device and

Abstract

Disclosed is a DASD access control method including storing information for identifying one data group in which an irrecoverable failure has occurred in the plurality of data groups stored in each of the first and second DASDs constituting the duplex DASD pair. A judgment is determined based on the stored information as to whether one data group has an irrecoverable failure which has occurred when the one data group held in either one of the first and second DASDs constituting the duplex DASD pair is accessed by one of the plurality of processing units. Access is allowed to the one data group in the one DASD by the one processing unit when the judgment results in that the one data group has no irrecoverable failure which has occurred therein. Finally, the access is stopped to the one data group when the judgment results in that the one data group has an irrecoverable failure which has occurred therein.