Browse Prior Art Database

Enhanced Catalog Recovery

IP.com Disclosure Number: IPCOM000040247D
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Branch, SM: AUTHOR [+4]

Abstract

A method is described for improving availability of a catalog system after a catalog failure, comprising the steps of: (a) limiting access to the catalog, allowing access only to maintenance programs performing recovery of the catalog; (b) recovering the catalog; and (c) orienting users of the catalog to the recovered catalog. Access to the catalog is limited by a locking mechanism. Users who perform catalog maintenance can execute programs to lock the catalog (i.e., allow exclusive use of the catalog to themselves) and recover the catalog. After a catalog is locked, unauthorized users are returned codes indicating that the catalog is unavailable for usage. Once the catalog has been recovered, an authorized user would unlock the catalog to allow other users continued access.

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Enhanced Catalog Recovery

A method is described for improving availability of a catalog system after a catalog failure, comprising the steps of: (a) limiting access to the catalog, allowing access only to maintenance programs performing recovery of the catalog; (b) recovering the catalog; and (c) orienting users of the catalog to the recovered catalog. Access to the catalog is limited by a locking mechanism. Users who perform catalog maintenance can execute programs to lock the catalog (i.e., allow exclusive use of the catalog to themselves) and recover the catalog. After a catalog is locked, unauthorized users are returned codes indicating that the catalog is unavailable for usage. Once the catalog has been recovered, an authorized user would unlock the catalog to allow other users continued access. If a catalog has been moved from its original physical location during recovery, its users must be reoriented when access to the catalog is resumed. This is accomplished by freeing all control blocks that were associated with the catalog prior to recovery and building new control blocks to reflect the newly recovered structure. As an illustration, consider the IBM Integrated Catalog Facility (ICF) which comprises a Basic Catalog Structure (BCS) and a VSAM Volume Dataset (VVDS). The BCS contains information about datasets that is non-volume specific and references the volume on which the dataset can be found. The VVDS resides on a particular volume and contains inform...