Operating Systems – Foundations of Modern Computing - MVS (Multiple Virtual Storage) Operating System

MVS: The Architectural Evolution of IBM Mainframe Operating Systems Multiple Virtual Storage, or MVS, is a foundational IBM mainframe operating system first launched in 1974 to succeed the OS/360 line. The provided text outlines the system's technical evolution, highlighting its ability to manage virtual memory across numerous separate address spaces to improve processing efficiency. Key features described include robust software recovery for fault tolerance, specialized record-oriented files known as data sets, and support for both batch and interactive workloads. Over several decades, the platform transitioned through major versions like MVS/XA and MVS/ESA, eventually incorporating UNIX support and expanding from 24-bit to 64-bit architecture. Today, the legacy of MVS continues through its direct modern descendant, z/OS, which maintains compatibility with older applications. The documents also touch on the system's global influence, noting historical industrial espionage cases that led to the creation of MVS-based forks by Japanese competitors.