Bmc Software, Inc.

Carla C Birk

Linda S Ball

William R Cunningham

Greg D Wood

Shawn B Wikle

A computer program operating in accordance with the invention monitors WRITE requests issued by a data-writing program that accesses data sets, e.g., for updating the data sets, and READ requests issued by a data-reading program that accesses data sets, e.g., for copying the data. While a series of READ requests (e.g., a data set copying operation) is in progress, the computer program monitors all WRITE requests issued for the data set in question by the data-writing program. If the data-reading program has not yet read the data portion (e.g., a data page) that is to be updated, the computer program selectively creates a cached image of the data portion as it existed at the beginning of the series of READ requests and delivers the cached image to the data-reading program, thereby reducing the potential for internal inconsistencies in the copied data. The computer program advantageously permits such caching to be performed without the need for specialized caching hardware.

Method of creating an internally consistent copy of an actively updated data set without specialized caching hardware

A computer performing a method in accordance with the invention receives from an end-user identifier(s) for one or more damaged (or otherwise unavailable) DASD volumes, and, optionally, an identifier for one or more DB2 subsystems. By searching and correlating DB2 and MVS data resources not residing on the damaged volume(s), the computer determines which object(s) on the specified damaged volume(s) are DB2 objects, and which DB2 subsystem(s) own each of these DB2 objects. A list of recoverable DB2 objects is created, and, optionally, provided to a recovery utility program for the purpose of facilitating recovery. The method permits identification of recoverable DB2 objects without needing access to the damaged or unavailable volumes, either before or after the volume failure, thereby advantageously enabling recovery methods after a volume failure has occurred.

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Austin, TX, United States of America

Carla C Birk