Browse Prior Art Database

Disaster Recovery Using Multiple Image Copies

IP.com Disclosure Number: IPCOM000121325D
Original Publication Date: 1991-Aug-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 1 page(s) / 30K

Publishing Venue

IBM

Related People

Haderle, DJ: AUTHOR [+4]

Abstract

This invention provides multiple, identical (image) copies of DB2* data sets, which contain the data stored in a DB2 relational database management system. All copies are identical and are produced in parallel. One or more of the copies are used for disaster recovery at the local site, for example, when a processor or DASD fails. Other of the image copies are used for disaster recovery at a remote site when the active local site cannot be used, for example, in the event of fire, flood and the like. The parallel production of the multiple image copies is significantly faster than sequential production of the same number of copies.

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Disaster Recovery Using Multiple Image Copies

      This invention provides multiple, identical (image)
copies of DB2* data sets, which contain the data stored in a DB2
relational database management system.  All copies are identical and
are produced in parallel.  One or more of the copies are used for
disaster recovery at the local site, for example, when a processor or
DASD fails.  Other of the image copies are used for disaster recovery
at a remote site when the active local site cannot be used, for
example, in the event of fire, flood and the like.  The parallel
production of the multiple image copies is significantly faster than
sequential production of the same number of copies.

      During recovery, a first (primary) copy of the data set is
used.  When there is an error with the primary copy, the backup image
copy is used beginning at the point where the error in the primary
copy occurred.  This use of a backup copy avoids the need to repeat
log processing for the items previously recovered from the primary
copy.

      The system keeps track of copies that are made, and during
recovery automatically locates all copies needed for recovery.

      In previous releases of DB2, the user was required to keep
track of data set copies made for recovery.  This invention reduces
that burden significantly.
*  Trademark of IBM Corp.