z/VM Module 1: Introduction

1. z/VMModule 1: Introduction The basic concepts and fundamental ideas of z/VM

2. IBM, DFSMS/VM, Hipersockets, z/OS, zSeries, z/VM, GDPS, Parallel Sysplex and Tivoli are trademarks of International Business Machines Corporation in the United States, other countries, or both. Microsoft and Windows are trademarks of Microsoft Corporation in the United States, other countries, or both. Java and all Java-based trademarks are trademarks of Sun Microsystems, Inc. in the United States, other countries, or both. Other company, product or service names may be trademarks or service marks of others. Trademarks

3. Objectives • What we should be able to do: • Describe z/VM is and its benefits as an operating system • Describe a virtual machine and what it does • Describe the differences between a first level guest and a second level guest • Define what is meant by virtualization technology • List four hardware resources that z/VM “virtualizes” • Name three examples of Virtualization and describe each • List three advantages that can be obtained by using Virtual Machines

4. Objectives continued • Define the following, note their differences, and tell how each is used: • SAF • IFL • LPAR • Describe the three different types of operating environments for z/VM • Describe the conditions that led to the development of virtualization technology

5. What is z/VM? • An operating system (VM = virtual machine) • A hypervisor, which refers to a system that virtualizes the real hardware environment • Runs on the zSeries architecture created by IBM • Latest version is Version 4, Release 4

6. z/VM as an Operating System • A highly flexible test and production environment • Has the ability to run multiple machine images and architectures • Can simplify the migration from one release to another

7. z/VM as an Operating System (2) • Running an operating system in a virtual machine should be the same as running an operating system on a real processor • Storage, processors, and I/O devices should behave in the same way on a virtual machine as on a real one • z/VM’s user interface is its Control Program (CP) commands

8. General z/VM Environment

9. What are Virtual Machines? • z/VM uses real resources to create virtual machines that include processors, memory, I/O devices, and networks • Virtual machines run as if a guest system was running on the real hardware • Virtualization Technology creates an illusion that z/VM uses to virtualize hardware components • VM allows users to run multiple copies and different types of operating systems on the same mainframe system

10. Creating System Level

11. z/VM – Virtualization Technology • Can reduce system administration costs for: • Planning • Purchasing • Installing new hardware

12. Processor Virtualization • The central processor is the core for: • The real machine • The virtual machine • Virtualization features: • Makes the guest operating system believe that it has exclusive control of the processors • Actually the processors are being shared among many operating systems

13. Memory Virtualization • This diagram shows the translation process. • Several different levels of translation are needed: • Machine • Physical memory • Virtual memory

14. Physical Storage Direct Access Storage Devices (DASD) are the main storage device Minidisks are the partitions of the DASD storage device These are the physical storage devices that can be virtualized to obtain virtual storage devices Virtual Storage Virtual disks are high speed disks that perform and are capable of the same operations as the physical storage devices If you have a CP failure or shutdown all virtual devices are lost Virtual storage increase performance and can increase total size of storage devices Storage Virtualization

15. I/O Virtualization • I/O devices that can be virtualized: • Ethernet NIC (network interface card) • Game port controller • Serial controller (COM) • Parallel controller (LPT) • Keyboard controller • I/O to device that can be virtualized: • Video adapter • Mouse and keyboard • Console interface

16. Examples of Virtualization-VTAPES • Virtual tapes • You can define and use virtual tape drives as if they were real tape drives • Like real tapes, virtual tapes can be: • Mounted • Written • Rewound • Read • Unloaded • When a virtual tape is no longer required, it can be scratched

17. Three Advantages of Using VM • Highly flexible environment • Multiple machine images • Many guest utilizing the same hardware • Consolidates resources • Cuts down on physical resources and space • Condenses many operating systems into one server • Increased performance • Enhancement for z/VM 4.3 is its Timer Management • Reduces bottlenecks and increases performance

18. Important Building Blocks of z/VM • SAF • System Administration Facility • Similar to the Virtual Image Facility (VIF), an earlier component • Has additional tools that provide: • Easy migration for your existing Linux distribution • Configuration files • Linux images • Data to z/VM • Comes standard with all z/VM 4.2, 4.3 and 4.4 packages

19. Important Building Blocks z/VM • IFL • Integrated Facility for Linux • Dedicated Linux engine for processing only Linux workloads • Supports: • Linux applications • Linux operating systems • Linux operating system in conjunction with z/VM • IBM’s IFLs are managed by PR/SM as a logical partition with dedicated CPUs

20. Important Building Blocks z/VM • Logical Partitions (LPARs) • Provide the ability to share a single server among separate operating system images • Help create a secure computing environment • Processors can be dedicated or shared • Can have multiple LPARs per server (up to 15 LPARs in a z900 server and up to 30 LPARs in a z990 server) • Used in environments where separation of workloads is required, but where the use of a single hardware platform is desired

21. Virtual: (z/VM) Can be functionally richer than a real environment Simulates hardware that does not have to exist in the real system, such as virtual tapes Can share a single copy of an application with many users Real: (LPAR) Has limitations depending on the hardware Hardware necessary to accomplish your task can be expensive Supports only one application for a single user Virtual versus Real Environments

22. Operating Environments • Logical Partitions (LPAR) • Hardware partitioning that enables up to 30 "logical partitions“ in the z/Architecture • Each LPAR runs a separate operating system • Each LPAR can run a different operating system • Virtual Partitions (z/VM) • zSeries virtualization technology • Supports large numbers of Linux images and other operating systems • Provides management capabilities • Very flexible; great for server consolidation

23. Running z/VM on an LPAR • Logical partitions (LPARs) can over time reduce costs and increase flexibility • z/VM on LPARs gives users better security with more control

24. How z/VM Fits with z/Architecture

25. Changes and Growth of z/VM

26. Versions and Releases • Version changes: • Indicate a significant change in capabilities • May also change the software price • Releasechanges: • Indicate that an incremental change has been implemented • Point Release changes: • Indicate a service release or update

27. z/VM Version 4 Release 3-Expanding Virtualization Technology • Virtualization Technology exploitation • Accounting of Virtual network resources • I/O priority queueing • Improved DASD and minidisk cache • Connectivity Enhancements • Multicast support for HiperSockets • Simulation of a QDIO network adapter • System Management Improvements • Better utilization of large real storage • RACF for z/VM as an optional, priced feature

28. z/VM Version 4 Release 4 – Improves Virtualization Capabilities for Linux onzSeries • Virtualization Technology and Linux Enablement: • Helps reduce overhead and may improve performance of virtual machines on z990 servers • Manages large numbers of virtual machines with high efficiency • Network Virtualization Enhancements: • Additional network-traffic configuration options using Virtual LANs (VLANs) and Virtual Switching • Extended HiperSockets support • Technology Exploitation – Support for IBM z990: • Improved logical-partitioning scalability with Logical Channel SubSystems (LCSS) • Improved capacity planning and I/O performance measurements • Supports up to 30 logical partitions (LPARs)

29. Key Concepts • Virtual machines emulates hardware and allows multiple users to use the same hardware components • The importance of virtual machines: • Virtual machines (VM) run as they were running on the real processor • Can use hardware that does not have to exist in the real system by simulation and virtualization • Virtual Machines can share a single copy of an application

30. Key Concepts continued • What is Virtualization Technology: • With virtualization technology, z/VM users can easily create many virtual machines consisting of: • Virtualized processors • Virtualized memory • Virtualized storage • Virtualized I/O resources • These can reduce administration costs and the overhead of planning, purchasing, and installing new hardware to support new workloads.

31. Key Concepts continued • The different types of environments: • Logical Partitions (LPARs) • Each of which runs a separate operating system • Virtual Partitions (z/VM) • Support for large numbers of Linux images and other operating systems • Running z/VM on a LPAR • z/VM on LPARs gives users better security with more control

32. Conclusion While z/VM has proven itself as an advanced technology, cost effective tool for server consolidation for over 30 years, the advent of Linux running on IBM mainframes has created a new awareness and new demand for the power and flexibility of the IBM virtualization operating system. z/VM provides not only the ability to share hardware and software resources, it also gives the users maximum flexibility to respond to today’s business challenges.

33. Glossary • Conversational Monitor System (CMS)- A component of z/VM that runs in a virtual machine and provides both the interactive z/VM end-user interface and the general z/VM application programming interface. CMS runs only under the control of the z/VM Control Program (CP). • Control Program (CP)- A component of z/VM that manages the resources of a single computer so that multiple computing systems appear to exist. Each apparent system, or virtual machine, is the functional equivalent of the real computer, and CP simulates the real machine architecture in the virtual machine. • Direct Access Storage Device (DASD)- A mass storage medium in which the data access time is effectively independent of the data location. Analogous to the hard drive in a personal computer system. • HiperSockets- A hardware channel that provides high-speed TCP/IP communication between logical partitions (LPARs) on the same IBM zSeries server. It uses an adaptation of the queued direct I/O (QDIO) architecture. • Hypervisor- has the ability to present virtual images of hardware control using Control Program (CP) commands. • Integrated Facility for Linux (IFL)- a dedicated processor that handles Linux-only workloads

34. Glossary continued • Logical PARtition (LPAR)- A subset of the processor hardware that is defined to support the operation of a system control program (operating system). • Minidisks- a logical subdivision of a direct access storage device. • OS/390- an operating system on the S/390 architecture. • Queued Direct I/O (QDIO)- A hardware channel architecture for direct data exchange with I/O devices, where both the I/O device and the program running on the server refer to main storage directly through a set of data queues. The QDIO architecture is used by Open Systems Adapter-Express (OSA-Express), HiperSockets, and Fibre Channel Protocol (FCP) channels. • Remote Access Control Facility (RACF)- a mainframe security product that can run on z/VM. • Real machine – refers to a single operating system that has exclusive usage of the underlying hardware system. Personal computers operate as real machines.

35. Glossary continued • Release- an incremental set of changes to a level of software. • Restructured EXtended eXecutor (REXX)- a programming language that uses English-language like statements. • System 360- the first mainframe architecture, which was created to run multiple discrete workloads. • Transaction Processing Facility (TPF)- an operating system that provides real time, high volume transaction processing capability. • Version- a significant change in software product capability. May be associated with an increase in software price. • Virtualization- A technology that facilitates the creation of many virtual machines, consisting of virtualized processors, communications, storage, and I/O resources, on a single hardware system. The technology allows virtual machines to use hardware components, but they are indirectly accessed through virtualization.

36. Glossary continued • Virtual images- copies of hardware that reflect the underlying system architecture. • Virtual machine- (1) A virtual data processing system that appears to be at the exclusive disposal of a particular user, but whose functions are accomplished by sharing the resources of a real data processing system. (2) In z/VM, the virtual processors, virtual storage, virtual devices, and virtual channel subsystem that CP allocates to a single user. A virtual machine also includes any expanded storage dedicated to it. • VM/ESA- An earlier version of z/VM for 31-bit architecture systems. • Virtual Storage Extended/Enterprise System Architecture (VSE/ESA) - an operating system that runs on S/390 and 31-bit architecture-capable zSeries systems. Supports small and medium business applications.

37. Glossary continued • z/Architecture- An IBM mainframe computer and operating system architecture that includes most of the facilities of S/390 and provides significant extensions such as 64-bit registers and addressing. • z/OS- a mainframe operating system that supports both older COBOL-based applications and newer internet and Java-enabled applications, providing a comprehensive and diverse application execution environment. z/OS 1.4 is available on the Marist z900 server. • z/OS.e- a specially-priced version of z/OS that provides select z/OS functions for the z800 and z890 processors. • z/VM- an operating system that runs on zSeries mainframe servers. It takes advantage of the 64-bit capabilities of z/Architecture.