No matter what utility is used to perform the backup and recovery of a catalog, the process isnt complete until the catalog is resynchronized with the data sets as they currently exist. Between the time the catalog was backed up and restored, data sets have been deleted and defined and the catalog has to be updated to reflect these changes. These changes to catalogs, or catalog events, are recorded in SMF records. The SMF record types for catalog events are:

61 - When records are added to the BCS during DEFINE

65 - When records are deleted or updated in the BCS

66 - When changes are made to the BCS during ALTER processing

With these records, the information for catalog re-synchonization is available, but there is still a need for a facility that can use this information to update the catalog quickly. Using these records without a tool designed to process them is possible, but is time consuming and laborious.

There are products available such as the Integrated Catalog Facility Recovery Utility or ICFRU - (5798-DXQ) that provide this capability. Combined with a regular program of catalog diagnostics and backups, proper recording, dumping and tracking of data from SMF, it is possible to shorten the time of a catalog outage.

31.9.1.3 Checking a VSAM KSDS for Structural Errors

AMS provides the EXAMINE command which can be used to analyze and report on the structural integrity of the index and data components of VSAM KSDS clusters and the basic catalog structure (BCS) of an ICF catalog.

EXAMINE INDEXTEST examines the index component of a KSDS by cross-checking vertical and horizontal pointers contained within the index control intervals.

EXAMINE DATATEST evaluates the data component of a KSDS by sequentially reading all data control intervals, including free space control intervals.

Messages describing errors or inconsistencies are generated during EXAMINE processing as that condition is detected. For more information concerning the EXAMINE command, refer to DFSMS/MVS Access Methods Services for ICF, SC26-4906.

31.9.2 DFSMShsm

DFSMShsm has its own set of diagnostic aids that can be used by a system programmer when diagnosing problems. The DFSMS/MVS DFSMShsm Diagnosis Reference, LY27-9608 provides information about DFSMShsm control blocks and data areas used during diagnostic and maintenance procedures. The DFSMShsm Diagnosis Guide, LY27-9607 provides instructions for diagnosing errors such as building keyword strings.

The DFSMS/MVS Managing Data Availability, SC26-4928 provides information about disaster prevention and the recovery of DFSMShsm data based on real experiences.

Chapter 31. Diagnosing System Problems 477

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IBM OS/390 manual DFSMShsm, Checking a Vsam Ksds for Structural Errors

OS/390 specifications

IBM OS/390, a versatile operating system, was a cornerstone in enterprise environments and played a pivotal role in mainframe computing. Released in the mid-1990s, OS/390 combined the strengths of IBM's MVS (Multiple Virtual Storage) with new features and enhancements, targeting scalability, reliability, and performance in demanding business applications.

One of the key features of OS/390 was its robust support for multiple users and processes. The system allowed thousands of concurrent users to access applications and data, ensuring high availability and minimizing downtime—a critical requirement for many large organizations. This scalability was supported through various enhancements in memory management and processor scheduling, enabling optimal resource allocation across diverse workloads.

OS/390 was known for its superior workload management capabilities. The Workload Manager (WLM) component allowed administrators to define service policies, specifying how system resources would be allocated according to the priority of tasks. This ensured that critical business processes received the necessary resources while less critical tasks were managed more flexibly.

Another significant characteristic of OS/390 was its commitment to security. The operating system provided comprehensive security features, including user authentication, data encryption, and auditing capabilities. This focus on security was vital for organizations handling sensitive data, ensuring compliance with regulations and safeguarding against unauthorized access.

OS/390 also supported advanced technologies that facilitated integration and development. The system included features like the IBM CICS (Customer Information Control System) for transaction processing and IMS (Information Management System) for database management. These technologies allowed organizations to build robust, high-performance applications tailored to specific business needs.

The ease of network integration was another strength of OS/390. With the advent of the Internet and global connectivity, OS/390 systems could easily interface with various network protocols, enabling businesses to operate in a connected world. This inclusion paved the way for many organizations to expand their capabilities and offer new services, driving digital transformation.

In conclusion, IBM OS/390 represented a significant advancement in mainframe technology, combining scalability, security, and robust workload management. Its rich feature set and support for critical enterprise applications solidified its role as a vital component of many organizations' IT infrastructures, ensuring they could meet their operational challenges head-on while supporting future growth. As technology continues to evolve, the legacy of OS/390 remains influential in the realm of computing.