Migrating copies of VSE production files, needed for regression tests, to OS/390

Migrating copies of VSE production databases, needed for regression tests, to OS/390

The conversion project team meets regularly to review the progress and status of the OS/390 tests. OS/390 tests typically take three to five months. The OS/390 test phase is complete when scheduled tests have been successfully performed.

32.5.4.4 OS/390 Automated Operations Tools

The objective of this task is to populate the OS/390 job scheduler, report/output manager and tape manager with job scheduling instructions, report/output management instructions and cataloged data coming from VSE.

Batch and online tests are coordinated to verify the integration of batch and online applications. The tools selected for OS/390 operations (for example, tape manager, job scheduler, job preparation and restart systems, EDI, and report manager) are used for the batch functional and production tests in order to validate their installation and setup.

If a report manager was used under VSE, the VSE report manager rules are migrated to the OS/390 report manager either from the VSE job scheduler (if applicable) or from operations manuals. During JCL conversion, the

JCL-managed reports are retrieved and identified with unique report-ids. Their attributes (form number, number of copies, FCB, remote destination, output class, and so on) are collected into a file used to load the OS/390 report manager. The OS/390 JCL is generated free of report management attributes but containing the report-ids instead.

Active VSE tape files are the files that will be read after switchover by the generated OS/390 JCL. Inactive VSE tape files are all the other files cataloged to the VSE tape manager.

Once identified through JCL conversion, active tape files are either:

Copied with reformatting (new OS/390 data set name and attributes) during switchover, if time allows, to an OS/390 tape volume, and cataloged to the OS/390 catalog and OS/390 tape manager, or

Cataloged with a ²marking² (for example by using a dedicated generic UNIT name like ²VSETAPE²) to the OS/390 catalog and OS/390 tape manager. A job service step is inserted at the start of each job to identify marked input tape file, if any, to modify the OS/390 JCL so that it can read the VSE-created file with its old VSE attributes and name. It takes only a few OS/390 production cycles for all VSE-created tape files to become obsolete and be replaced by a new OS/390-created version. Most VSE-created tape files have disappeared within a month after switchover, after daily, weekly, biweekly and monthly jobs have read the last VSE-created version of the file.

The list of inactive tape files (files not connected to the JCL converted to OS/390) is manually reviewed to identify, long before switchover, the legal archive and other files that do need to be migrated to OS/390. Those files can be copied to OS/390 tapes during the weeks and days before switchover, or left on VSE tapes and cataloged as is to the OS/390 catalog.

510VSE to OS/390 Migration Workbook

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IBM manual 32.5.4.4 OS/390 Automated Operations Tools

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.