Method and system for sidefile status polling in a time zero backup copy process

USRE37364E · kind E · reissue

Assignee

• International Business Machines Corporation · US

Inventors

• Oded Cohn · Haifa, IL
• Michael H. Hartung · Tucson, US
• William Frank Micka · Tucson, US
• John Norbert McCauley · Tucson, US
• Claus William Mikkelsen · San Jose, US
• Kenneth Nagin · Haifa, IL
• Yoram Novick · Cupertino, US
• Alexander Winokur · Haifa, IL

Key dates

• Filing date: Aug 31, 1995
• Grant date: Sep 11, 2001
• Expiry date: Aug 31, 2015

Classification

• Technology area (CPC —): General

Abstract

A method and system are disclosed for enhanced efficiency of backup copying of designated datasets stored within a plurality of storage devices coupled to the data processing system via a storage subsystem control unit having subsystem memory therein. Application execution within the data processing system is temporarily suspended long enough to form a dataset logical-to-physical system address concordance to be utilized to administer copying of the designated dataset. Thereafter, application initiated updates to uncopied portions of the designated datasets are temporarily deferred until sidefiles of the affected portions of the designated datasets are written to subsystem memory. The updates are then written to the storage subsystem. Portions of the designated datasets are then accessed and copied from the storage subsystem on a scheduled or opportunistic basis utilizing selected data retrieval command sequences. A sidefile status query is appended to selected data retrieval command sequences and the presence of data within the subsystem memory is determined without the necessity of additional communications between the data processing system and the storage subsystem. The sidefil…