Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtualization
Chapter 19
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Overview
Fourth Edition (Exam 220-802)
• In this chapter, you will learn how to
– Describe the concepts of virtualization
– Explain why PC and network administrators have
widely adopted virtualization
– Describe how virtualization manifests in modern
networks
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Introduction to Virtualization
Fourth Edition (Exam 220-802)
• Virtualization is the “next big thing” in
the computer industry.
– Virtualization creates a complete environment for a
guest operating system to function as if it were
installed on its own computer.
– Guest environment is called a virtual machine
(VM).
– Individual machines or entire networks can be
virtualized.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Introduction to Virtualization
(continued)
Figure 1: VMware running Linux
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
What Is Virtualization?
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
What Is Virtualization?
Fourth Edition (Exam 220-802)
• Most people have heard of “virtual
reality.”
– A “virtual” world is created by software, with sight
and sound provided by video and audio equipment.
– Primarily used for gaming, flight simulation, etc.
– Equipment such as goggles and special gloves
enables you to “see” and “move” objects.
• Computer virtualization is similar
– “Virtual” operating system
– Software computer (guest) running on hardware
host
– Allows multiple different operating systems to run
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
What Is Virtualization?
(continued)
Figure 2: Virtual reality training (photo courtesy of NASA)
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
What Is Virtualization?
(continued)
Figure 3: Using virtual reality to practice spacewalking (photo courtesy of NASA)
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Computer Virtualization
Fourth Edition (Exam 220-802)
• Similarly, computers and networks can
be virtualized.
– Virtualization convinces an operating system that
it’s running on its own hardware.
– The virtualization software runs on a host operating
system that is physically installed on a machine.
– The guest operating systems are the virtual
machines.
– Virtualization uses hypervisors or virtual machine
managers to create and manage virtual machines
and their interactions with their host environments.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Meet the Hypervisor
Fourth Edition (Exam 220-802)
• A normal OS uses a program called a
supervisor.
– Handles very low-level interaction among hardware
and software (i.e., task scheduling, allotment of
time and resources, etc.)
• Full virtualization requires an extra layer
of programming to manage the complex
interactions between the host and guest
machines.
• Enter the hypervisor or virtual machine
manager (VMM).
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Meet the Hypervisor
(continued)
• The hypervisor handles the input and
output requests an operating system
would make of normal hardware.
• It allocates real hardware (drives, RAM,
media, etc.) from the host to the virtual
machines.
• It enables easy addition and removal of
virtual hard drives, virtual network
cards, virtual RAM, etc.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Meet the Hypervisor
(continued)
Figure 4: Configuring virtual hardware
in VMware Workstation
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Meet the Hypervisor
(continued)
Figure 5: System setup utility in VMware Workstation
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Emulation vs. Virtualization
Fourth Edition (Exam 220-802)
• Virtualization uses hardware from the
host system and divides it into individual
virtual machines.
– It abstracts hardware that runs on the same
platform.
– It cannot virtualize hardware that is on a different
platform (an Intel platform cannot virtualize a Sony
PlayStation).
• Emulation is very different.
– It enables software written for a different platform
to run, but it does not virtualize the hardware.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Emulation vs. Virtualization
(continued)
• An emulator is software or hardware
that converts the commands to and from
the host machine into an entirely
different platform.
– For example, an emulator makes it possible to run
game console software on a PC.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Emulation vs. Virtualization
(continued)
Figure 6: Super Nintendo emulator running on Windows
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Sample Virtualization
Fourth Edition (Exam 220-802)
• The following slides take you through a
quick tour of virtualization.
– They show the steps involved in setting up and
installing a virtual machine and its guest OS.
• In this example, Windows 7 is the host
OS.
• VMware Workstation is the VMM.
• Ubuntu is installed as the guest OS.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Sample Virtualization
(continued)
Figure 7: VMware Workstation
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Sample Virtualization
(continued)
Figure 8: Selecting a Typical or Custom setup
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Sample Virtualization
(continued)
Figure 9: Selecting the installation media
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Sample Virtualization
(continued)
Figure 10: Setting the virtual drive size
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Sample Virtualization
(continued)
Figure 11: Entering the VM name and location
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Sample Virtualization
(continued)
Figure 12: Ubuntu installing into the new virtual machine
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Sample Virtualization
(continued)
Figure 13: VMware Workstation with a single VM
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Sample Virtualization
(continued)
Figure 14: POST in a virtual machine
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Why Do We Virtualize?
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Why Do We Virtualize?
Fourth Edition (Exam 220-802)
• Virtualization provides two key benefits:
– It reduces the number of physical machines.
– Virtual machines are simply files, making it easy to
manage backups, security, portability, etc.
• Other important reasons include
–
–
–
–
–
Power savings
Hardware consolidation
System recovery
System duplication
Research
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Power Savings
Fourth Edition (Exam 220-802)
• Before virtualization, each server OS
required its own unique physical system.
• With virtualization, you can place
multiple virtual servers on a single
physical system, reducing electrical
power use.
• Expanding this electricity savings over
an enterprise network or on a data
center is cost effective and “green.”
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Hardware Consolidation
Fourth Edition (Exam 220-802)
• A physical high-end server represents a
substantial investment in hardware—
multiple processors, RAID arrays,
redundant power supplies, and RAM.
Setting up multiple physical high-end
servers can be very expensive.
• Virtualization makes it possible to
increase RAM and run a number of
servers on a single machine.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
System Recovery
Fourth Edition (Exam 220-802)
• The most popular reason for virtualization
is to keep a high uptime percentage.
• If a system goes down, you need to
quickly restore the system from a backup.
• Virtualization makes it possible to shut
down the VM and reload an alternative
copy.
• Snapshots enable you to make a point-intime exact copy of the virtual machine
that can be used in case of an emergency
restore.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
System Recovery
(continued)
Figure 15: Saving a snapshot
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
System Duplication
Fourth Edition (Exam 220-802)
• VMs are simply files that can be copied.
• VMs can be mass-duplicated by copying
the files to the target machine.
• This makes it possible to deploy
numerous servers with similar baseline
operating systems.
– Useful in research or teaching environments
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Research
Fourth Edition (Exam 220-802)
• Virtualization makes it possible to reduce
the number of research and testing
machines.
• It can streamline the equipment
necessary in these areas:
– Product testing and research
– Security testing and research
– Development testing before production
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Research (continued)
Fourth Edition (Exam 220-802)
Figure 16: Lots of VMs used for research
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtualization in Modern Networks
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtualization in Modern
Networks
• The products we’ve discussed so far offer
virtualization over operating systems:
– VMware Workstation
– Microsoft Virtual PC
• They are suitable for small
implementations with few virtual
machines.
• Large-scale implementations require a
different approach.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtualization in Modern
Networks (continued)
• Virtualization in large-scale networks
uses “bare-metal” hypervisors.
– No operating system is necessary.
– The virtualization software is the OS.
– The hypervisor eliminates all the unnecessary OS
overhead.
• VMware introduced ESX in 2001.
– It was an early serious large-scale bare-metal
hypervisor.
– It has a small storage footprint and can be installed
on and booted from a USB flash drive.
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtualization in Modern
Networks (continued)
Figure 17: USB drive on server system
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
VMMs vs. Hypervisors
Fourth Edition (Exam 220-802)
• A virtual machine manager (VMM) is
virtual machine software that runs on
top of a host operating system.
– Example: VMware Workstation
• A hypervisor is software that does not
need a host operating system.
– Example: ESX Server
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Virtual Machine Managers
Fourth Edition (Exam 220-802)
• Many choices are available for Linux,
Windows, and Mac OS:
–
–
–
–
VMware Workstation
Microsoft Virtual PC
Parallels
KVM
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtual Machine Managers
(continued)
• VMware Workstation
– Industry leader in virtualization
– Comes in versions for Linux and Windows
– Offers features such as VMTools that make
interactions between guest and host OS seamless
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtual Machine Managers
(continued)
• Virtual PC
– Microsoft VMM that runs over various iterations of
Windows
– Free product
– Some limitations
• Officially supports Windows VMs, but Linux VMs can
be installed and managed
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtual Machine Managers
(continued)
Figure 18: Windows Virtual PC
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtual Machine Managers
(continued)
• Parallels
– Most popular virtualization manager for Mac OS X
(followed by VMware Fusion)
– Supports all popular operating systems and even
has good 3-D graphics support
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtual Machine Managers
(continued)
Figure 19: Parallels for Mac
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Fourth Edition (Exam 220-802)
Virtual Machine Managers
(continued)
• KVM
–
–
–
–
Open-source virtualization product from Red Hat
Represents Linux/Unix world
Supports a few non-x86 processors
Other open-source contenders include Xen and
Oracle’s VirtualBox
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Hypervisors
Fourth Edition (Exam 220-802)
• There are several choices, but two are
dominant in the market:
– Vmware’s ESX
– Microsoft’s Hyper-V
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Hypervisors (continued)
Fourth Edition (Exam 220-802)
• ESX
– Market leader; offers several features:
• Support for large storage (SAN and NAS)
• Transparent and automatic fault tolerance
• Transparent server transfer—you can move a running
VM from one machine to another
• Support for up to 32 CPUs, depending on the version
© 2013 The McGraw-Hill Companies, Inc. All rights reserved
Mike Meyers’ CompTIA A+®
Guide to 802:
Managing and
Troubleshooting PCs
Hypervisors (continued)
Fourth Edition (Exam 220-802)
• Hyper-V
– Microsoft’s contender in virtualization
• Free product
• Previously only part of Windows Server 2008—now
also available as stand-alone product
• Available for 64-bit systems
© 2013 The McGraw-Hill Companies, Inc. All rights reserved