Operating Systems – Foundations of Modern Computing - z/VM : IBM VM operating system

z/VM: Mainframe Virtualization and Hypervisor Evolution Detail the IBM VM operating system family, tracing its historical roots from the early 1970s up to the contemporary product, z/VM. The foundation of this system is the Control Program (CP), which functions as a hypervisor to create full virtualization environments, enabling hundreds to thousands of virtual guest servers, including Linux, z/OS, and Red Hat OpenShift, to run efficiently on a single IBM Z or LinuxONE mainframe. Historically centered around the Conversational Monitor System (CMS), the operating environment utilizes unique file systems such as minidisks and the centralized Shared File System (SFS). IBM currently promotes z/VM as a highly scalable hypervisor that supports on-premises cloud foundations and provides extreme IT efficiency through resource sharing and elasticity. This virtualization platform is further supported by numerous specialized add-ons for systems management and backup and protection, ensuring continuous availability and simplified infrastructure oversight.