Abstract: A method and system for managing one or more coupling facilities in a data processing system. An active policy is used to control resources located in the coupling facilities. The active policy can be changed such that control of the resources can be altered. Compatible changes are made immediately and incompatible changes are made at a subsequent time. Recorded in the active policy and in the coupling facilities is information regarding the resources. When the information in the active policy is not in synchronization with the information in the coupling facilities, a reconciliation technique is performed. The resources in the coupling facilities can be modified but prior to the modification, the intended modifications are stored in the active policy.

Abstract: A Shared Data Access Serialization mechanism for sharing data among a plurality of systems while maintaining data integrity. User data is maintained on a primary and optionally an alternate data store. Each data store contains a set of lock blocks, one for each system sharing the data. The contents of the lock blocks, normally a time-of-day value, indicate system ownership status of the associated data. "Lock Rules" are disclosed for determining resource ownership, as well as a "lock stealing" mechanism for obtaining resource ownership from a temporarily stopped system. Suffix records and check records are used to insure data integrity. Error indications deduced from inconsistent suffix and/or check records are used to trigger a data recovery mechanism, and the recovery mechanism can synchronize a primary and secondary data store without the necessity of suspending access to the primary during the synchronization process.