z/VM

The z/VM architecture centers around the Control Program (CP), which provides the core virtualization and resource management capabilities. The CP manages the allocation of real storage, CPU cycles, and I/O resources to virtual machines. The Conversational Monitor System (CMS) provides a single-user operating system environment for application development and interactive computing.

The CP uses a command-line interface (CLI) for system management, with commands like 'QUERY' for status information, 'DEFINE' for virtual machine configuration, and 'IPL' to load guest operating systems. Storage is managed using DASD (Direct Access Storage Device), which is accessed through the CP. Each virtual machine has its own virtual storage space, mapped to real storage as needed.

Network communication is handled through TCP/IP, with virtual machines connecting to the network through virtual network adapters. Security is implemented using RBAC, with users assigned roles and permissions. Encryption is supported for data at rest and in transit, often leveraging hardware security modules (HSMs).

Audit logging is provided through SMF, which records system events and security violations. The z/VM architecture is designed for high availability and scalability, with features like live guest relocation and data replication. The system's design prioritizes efficient resource utilization and robust security within the mainframe environment.

Compared to other virtualization platforms, z/VM's integration with the IBM Z architecture and its focus on mainframe environments provide unique advantages.