Method and means for time zero backup copy of data

Abstract From the Canadian patent

Abstract of the Disclosure, Backup copying of designated datasets representing point in time consistency may be performed in a CPU on an DASD storage subsystem concurrent with CPU application execution by suspending execution only long enough to form a a logical to physical address concordance and thereafter physically backing up the datasets on the storage subsystem on a scheduled or opportunistic basis. Application initiated updates to the uncopied designated datasets are first buffered, sidefiles made of the affected datasets the, updates written through to the storage subsystem and the, sidefiles written to storage in backup copy order as controlled by the concordance.