z/VM running CMS fullscreen

Current version in IBM's VM family of virtual machine operating systems.

- Z/VM

56 related topics



Family name used by IBM for all of its z/Architecture mainframe computers.

A single-frame IBM z15 mainframe. Larger capacity models can have up to four total frames. This model has blue accents, as compared with the LinuxONE III model with orange highlights.
An IBM z14 mainframe. It is distinguished from the LinuxONE model by the blue accents on the doors.
A pair of IBM mainframes. On the left is the IBM z13 (while the naming was changed, the z13 line had a zSystems label on doors). On the right is the IBM LinuxONE Rockhopper.
A trio of IBM zEnterprise mainframe computers. From left to right: EC12, BC12, Bladecenter Extension.
An IBM zEnterprise EC12 with the cover removed. The interior is lit to better see the various internal parts.
IBM System z10
IBM System z9
An IBM zSeries 800 (foreground, left) running Linux
zBX extension

A hypervisor called z/VM can also be run as the second layer virtualization in LPARs to create as many virtual machines (VMs) as there are resources assigned to the LPARs to support them.

VM (operating system)

Family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers.

Teddy bear – VM's mascot since 1983.
The default login screen on VM/370 Release 6.
CMS starting up after the user MAINT (system administrator) has logged in.
The CMS editor on VM/370, editing a COBOL program source file.
Invoking the System/360 COBOL compiler on VM/370 CMS, then loading and running the program.
An example of a non-CMS guest operating system running under VM/370: DOS/VS Release 34. The DOS/VS system is now prompting the operator to enter a supervisor name to continue loading.
OS/VS1 starting under VM/370.
Using DASD Dump/Restore (DDR) to back up a VM/370 system.



IBM's 64-bit complex instruction set computer (CISC) instruction set architecture, implemented by its mainframe computers.

Front cover of the IBM S/390 Parallel Enterprise Server Generation 5

z/VM 6.4 fulfills Statement of Direction to drop support for all use of Expanded Storage.

Operating system

System software that manages computer hardware, software resources, and provides common services for computer programs.

OS/360 was used on most IBM mainframe computers beginning in 1966, including computers used by the Apollo program.
PC DOS was an early personal computer OS that featured a command-line interface.
Mac OS by Apple Computer became the first widespread OS to feature a graphical user interface. Many of its features such as windows and icons would later become commonplace in GUIs.
The first server for the World Wide Web ran on NeXTSTEP, based on BSD.
Ubuntu, desktop Linux distribution
Linux, a unix-like operating system was first time released on September 17, 1991, by Linus Torvalds. Picture of Tux the penguin, mascot of Linux.
A kernel connects the application software to the hardware of a computer.
Privilege rings for the x86 microprocessor architecture available in protected mode. Operating systems determine which processes run in each mode.
Many operating systems can "trick" programs into using memory scattered around the hard disk and RAM as if it is one continuous chunk of memory, called virtual memory.
File systems allow users and programs to organize and sort files on a computer, often through the use of directories (or "folders").
A screenshot of the Bash command line. Each command is typed out after the 'prompt', and then its output appears below, working its way down the screen. The current command prompt is at the bottom.
A screenshot of the KDE Plasma 5 graphical user interface. Programs take the form of images on the screen, and the files, folders (directories), and applications take the form of icons and symbols. A mouse is used to navigate the computer.

IBM CP-67 – IBM System/360, 1967 to IBM z/VM


Discontinued time-sharing operating system of the late 1960s and early 1970s, known for its excellent performance and advanced features.

VM/370's successors (such as z/VM) remain in wide use today.

IBM System/360 Model 67

Important IBM mainframe model in the late 1960s.

IBM System/360 Model 67-2 (duplex) at the University of Michigan, c. 1969
IBM System/360 Model 67-2 (duplex) at the University of Michigan, c. 1969
Left side, 2167 configuration console for the IBM/System 360 Model 67-2 (duplex) at the University of Michigan, c. 1969

Over time it evolved into a fully supported IBM operating system (VM/370 and today's z/VM).

Text editor

Type of computer program that edits plain text.

Editors like Leafpad, shown here, are often included with operating systems as a default helper application for opening text files.
A box of punched cards with several program decks.
Emacs, a text editor popular among programmers, running on Microsoft Windows
gedit is a text editor shipped with GNOME

Most such editors are derivatives of ISPF/PDF EDIT or of XEDIT, IBM's flagship editor for VM/SP through z/VM.


64-bit operating system for IBM z/Architecture mainframes, introduced by IBM in October 2000.

The z/OS welcome screen as seen through a terminal emulator. This classic interface is still available but Web access is common.
An IBM System Z10 mainframe computer on which z/OS can run.

However, modern IBM mainframes also offer two additional levels of virtualization: LPARs and (optionally) z/VM.

Oracle Solaris

Proprietary Unix operating system originally developed by Sun Microsystems.

Screenshot of Java Desktop System on Solaris 10
Screenshot of Java Desktop System on Solaris 10
olvwm with OpenWindows on Solaris
The Common Desktop Environment (CDE) was open sourced in August 2012. This is a screenshot of CDE running on Solaris 10.
Screenshot of the Java Desktop System (JDS) running on Solaris 10.
Solaris logo introduced with Solaris 10 and used until Oracle's acquisition of Sun
Solaris 2.4 via Telnet

On November 28, 2007, IBM, Sun, and Sine Nomine Associates demonstrated a preview of OpenSolaris for System z running on an IBM System z mainframe under z/VM, called Sirius (in analogy to the Polaris project, and also due to the primary developer's Australian nationality: HMS Sirius of 1786 was a ship of the First Fleet to Australia).

Core dump

In computing, a core dump, memory dump, crash dump, storage dump, system dump, or ABEND dump consists of the recorded state of the working memory of a computer program at a specific time, generally when the program has crashed or otherwise terminated abnormally.

Computer simulation, one of the main cross-computing methodologies.

These files can be viewed as text, printed, or analysed with specialised tools such as elfdump on Unix and Unix-like systems, objdump and kdump on Linux, IPCS (Interactive Problem Control System) on IBM z/OS, DVF (Dump Viewing Facility) on IBM z/VM, WinDbg on Microsoft Windows, Valgrind, or other debuggers.