z/VM Module 1: Introduction

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Nov 8, 2013 (3 years and 5 months ago)

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© 2004 IBM Corporation

IBM
^

z/VM

Module 1: Introduction

The basic concepts and fundamental
ideas of z/VM

© 2004 IBM Corporation

IBM
^


Trademarks


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.

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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


© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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


© 2004 IBM Corporation

IBM
^


General z/VM Environment

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


Creating System Level

© 2004 IBM Corporation

IBM
^


z/VM


Virtualization Technology



Can reduce system administration costs for:



Planning


Purchasing


Installing new hardware

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


Memory Virtualization


This diagram shows the
translation process.


Several different levels of
translation are needed:


Machine


Physical memory


Virtual memory

© 2004 IBM Corporation

IBM
^


Storage Virtualization


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

© 2004 IBM Corporation

IBM
^


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


© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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


© 2004 IBM Corporation

IBM
^


Virtual versus Real

Environments


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

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


How z/VM Fits with z/Architecture

© 2004 IBM Corporation

IBM
^

Changes and Growth of z/VM

© 2004 IBM Corporation

IBM
^


Versions and Releases


Version changes:


Indicate a significant change in capabilities


May also change the software price


Release

changes
:


Indicate that an incremental change has been implemented


Point Release changes:


Indicate a service release or update

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


z/VM Version 4 Release 4



Improves Virtualization Capabilities for
Linux on

zSeries


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)

© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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.

© 2004 IBM Corporation

IBM
^


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


© 2004 IBM Corporation

IBM
^


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.


© 2004 IBM Corporation

IBM
^


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

© 2004 IBM Corporation

IBM
^


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.

© 2004 IBM Corporation

IBM
^


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.

© 2004 IBM Corporation

IBM
^


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.

© 2004 IBM Corporation

IBM
^


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.