Part 4, Converting VSE Utilities to OS/390 Utilities

Conversion of the VSE utilities to their equivalent OS/390 utilities is discussed in this part.

Part 5, Setting Up the Migration Environment

No two Information Processing environments are alike. Hardware, software, scheduling, personnel needs will be different in all cases. This part discusses preparing for and tailoring the test environment, and various hardware/software combinations and activities that can be performed in parallel.

Part 6, Running Your OS/390 System

The OS/390 environment is much different than the VSE environment. This part provides an orientation to the use of TSO/ISPF, OS/390 console operation, and OS/390 utilities. Additionally, the systems management philosophy with OS/390 and diagnosing problems with OS/390 are discussed.

Part 7, Converting your Applications

This part discusses the application program conversion process and some of the conversion tools available.

Part 8, Migration Experience

An example of a migration plan for the ABC company is discussed in this part.

Part 9, Appendixes

The appendixes provide useful information including a list of helpful publications, education information, and a chart mapping Independent Software Vendor products to OS/390 products.

1.2Traditional Reasons for Migrating

Users migrating to MVS and OS/390 over the years have done so for a variety of reasons. While the purpose of this document is to concentrate on the hows of migrating and not so much the whys, it is interesting to note some of the more typical or traditional reasons that customers migrate to OS/390.

1.2.1 Business Consolidation

Corporations, more recently, have found themselves involved in business consolidation activities. Be it for economic and/or efficiency reasons companies have been faced with the challenge of effectively addressing this type of change. Consolidating the Information Technology infrastructure is just one of these challenges. Many have found that combining the system workloads from various parts of the newly consolidated organization has produced I/T system requirements beyond the capacity of the VSE operating system. For example, attempting to combine multiple VSE images into a single system image has often created situations where multiple processor (n-way) capacity is needed. Prior to the Turbo Dispatcher (n-way processor support) in VSE/ESA V2, OS/390 (or MVS/ESA) provided the only solution. Another issue associated with combining multiple images into a single system image has been the number of VSE partitions. Similar to the case of the Turbo Dispatcher, prior to dynamic partitions in VSE/ESA V1, OS/390 (or MVS/ESA) provided a solution to this issue.

4VSE to OS/390 Migration Workbook

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IBM OS/390 manual Traditional Reasons for Migrating, Business Consolidation

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.