1. Virtualization and Cloud Computing
Chapter 15

2. Objectives Describe the concepts of virtualization
Explain why PC and network administrators have widely adopted virtualization
Describe how virtualization manifests in modern networks
Describe the service layers and architectures that make up cloud computing

3. Overview

4. Introduction to Virtualization (1 of 2)
Virtualization uses special software running on a computer to create a complete guest environment
Functions as if installed on its own computer
The guest environment is called a virtual machine (VM)

5. Introduction to Virtualization (2 of 2)
Figure VirtualBox running Linux

6. Key Topics in This Chapter
What virtualization is and why we use it
Virtualization in modern networks
The role of virtualization in cloud computing
How cloud computing adds value to the Internet
How cloud networks compare to and interface with traditional networks and each other

7. Historical/Conceptual
What Is Virtualization?

8. What Is Virtualization? (1 of 3)
Most people have heard of “virtual reality”
Simulation of a world or environment
Software works with input from a headset to emulate a physical world
Used in flight simulation and astronaut training
Computer virtualization is similar
Virtualization convinces an OS it is running on its own hardware

9. What Is Virtualization? (2 of 3)
Figure Virtual reality training (Image courtesy of NASA)

10. What Is Virtualization? (3 of 3)
Figure Using virtual reality to practice spacewalking
(Image courtesy of NASA)

11. Meet the Hypervisor (1 of 4)
Extra layer of sophisticated programming
Manages complex interactions within the host
Handles every input and output the OS requests
Schedules tasks
Allots time and resources

12. Meet the Hypervisor (2 of 4)
A VMware Workstation hypervisor has functions of adding and removing:
Virtual hard drives
Virtual network cards
Virtual RAM
Virtualization provides virtualized BIOS and System Setup for every virtual machine
Note (p. 461): The host machine allocates real RAM and CPU time to every running virtual machine. If you want to run a number of virtual machines at the same time, make sure your host machine has plenty of CPU power and, more importantly, plenty of RAM to support all the running virtual machines.

13. Meet the Hypervisor (3 of 4)
Figure Configuring virtual hardware in VirtualBox

14. Meet the Hypervisor (4 of 4)
Figure 15.5 System Setup in VMware Workstation

15. Emulation vs. Virtualization (1 of 2)
Virtualization segments host hardware into individual virtual machines
A virtual machine acts like a host system (example: a host Intel system and a virtual machine that acts like the host Intel system)
Emulation converts commands to and from the host into an entirely different platform

16. Emulation vs. Virtualization (2 of 2)
Figure Super Nintendo emulator running on Windows

17. Desktop Virtualization (1 of 5)
Virtualization example
VMware workstation on a Windows system
Create a virtual machine running Ubuntu Linux
Steps
Obtain a copy of VMware Player (free)
Select Create a New Virtual Machine
Install the operating system; every VM requires a separate, legal copy of Windows

18. Desktop Virtualization (2 of 5)
Figure VirtualBox creating a new virtual machine

19. Desktop Virtualization (3 of 5)
Figure Starting the customization

20. Desktop Virtualization (4 of 5)
Figure 15.9 Dynamically sizing the virtual hard drive

21. Desktop Virtualization (5 of 5)
Figure Selecting the installation media

22. Test Specific
Why Do We Virtualize?

23. Why Do We Virtualize? Important things to keep in mind
A single hypervisor on a single system can run as many virtual machines as its RAM, CPU, and drive space allow
RAM is almost always the limiting factor
A virtual machine that has been shut down is little more than a file sitting on a hard drive

24. Reasons for Virtualization (1 of 3)
Power saving
Reduce power requirements of multiple servers
Hardware consolidation
System recovery
Simple to reload alternate copy of the OS
Option to save a snapshot periodically
Allowing quick return to that state at a later time

25. Reasons for Virtualization (2 of 3)
System duplication
VMs are files, so easily copied
Can add new installations easily
Research
Aids software troubleshooting by being able to keep active copies of specific operating system versions on a single machine

26. Reasons for Virtualization (3 of 3)
Figure Lots of VMs used for research

27. Virtualization in Modern Networks

28. Bare-Metal Hypervisor (1 of 2)
Products discussed so far offer virtualization over operating systems
A bare-metal hypervisor is installed on top of hardware only—no other software
Vmware introduced ESX in 2001
Supplanted by ESXi, a free hypervisor that replaces the host OS on a physical machine and provides a rudimentary interface

29. Bare-Metal Hypervisor (2 of 2)
Figure shows how we load our copy of ESXi: via a small USB thumb drive. Power up the server, the server loads ESXi off the thumb drive, and in short order a very rudimentary interface appears where we can input essential information, such as a master password and a static IP address.
Figure USB drive on server system

30. Hypervisors Bare-metal hypervisors on Intel-based systems
VMware’s ESXi
Microsoft’s Hyper-V
Citrix’s XenServer
Tech Tip: KVM (p. 466): There’s another open source Linux-based hypervisor you may run into—the Kernel-based Virtual Machine (KVM). The foundation of a modern OS, the kernel, handles very low-level interactions among hardware and software like task scheduling and the allotment of time and resources; as its name implies, KVM is closely integrated with Linux’s kernel. While it may not be as popular as the other hypervisors, the fact that it’s built into Linux means you could run into it almost anywhere.

31. Administering a Hypervisor (1 of 2)
Typically administered using tools running on a client computer
Used for occasional maintenance and administration
Examples
VMware’s vSphere Client
Microsoft’s Hyper-V Manager

32. Administering a Hypervisor (2 of 2)
Figure VMware vSphere Client

33. Scaling Virtualization (1 of 2)
Virtualization increases flexibility as the scale of an operation increases
VMs can be distributed across hosts
Adding more and more VMs needing different amounts of resources
Increases the options for distributing them across the hosts to minimize unused resources

34. Scaling Virtualization (2 of 2)
Figure No vacancy on these hosts

35. Data Storage Storage is usually separate from the host
Storage area network
Server that presents a pool of hard disks over the network as any number of logical disks
Reads and writes at the block level
Acts like a virtual disk

36. Storage Area Networks Supporting infrastructure options for a SAN
Fibre Channel (FC)
Designed for high performance storage
Internet Small Computer System Interface (iSCSI)
Built on top of TCP/IP
Performance can suffer, partly from processing frame headers; can use jumbo frames to reduce total number of frames moving through the network
InfiniBand competes with FC and iSCSI
Provides interconnect between storage arrays and servers

37. Network Attached Storage
Dedicated fileserver with its own file system
Uses hardware and software designed for serving and storing files
Must perform file system work, reducing performance
Exam Tip (p. 469): There is no difference between a virtual NIC and a physical NIC, once properly configured. Virtual NICs have MAC addresses just like a physical NIC. You set up everything about a virtual NIC: IP address, subnet mask, etc., exactly as you do with a physical NIC.

38. Virtual Networking
Software running network devices can be run in a virtual machine
Virtual networking components live on the hypervisor with the virtual servers they support

39. Virtual Switches (1 of 3)
Addresses problems with multiple VMs needing access to the Internet
However, a physical server only has a single NIC
Two ways virtualization gives individual VMs valid IP addresses
Bridge the NIC
Connect with a virtual switch

40. Virtual Switches (2 of 3)
Special software that does the same Layer 2 switching a hardware switch does
Including features like VLANs
When the NICs are bridged, the VMs and the host’s NIC are all connected to the virtual switch
Cross Check: Switches (p. 486)
You’ve read about switches since Chapter 2, Network Models, and again in Chapters 4 and 12, so check your memory now. What OSI layer do switches work? Why is that a trick question? How do you manage a switch?

41. Virtual Switches (3 of 3)
Figure Virtual switch

42. Distributed Switches (1 of 2)
Virtual switches normally use a Web interface for configuration.
Quick growth requires careful configuration for every new virtual switch added to existing virtual switches in a large, complex single virtual network.

43. Distributed Switches (2 of 2)
Distributed switching; the centralized installation, configuration and handling of every switch in a network.
Every hypervisor has some form of central configuration of critical issues for switches, such as VLAN assignment and trunking.
Cross Check (p. 470):
Switches
You first read about switches in Chapter 1, “Network Models,” and again in Chapter 3, “Ethernet Basics,” and Chapter 11, “Advanced Network Devices.” Check your memory now. At what OSI layer do switches work? Why is that a trick question? How do you manage a switch?

44. Virtual Routers and Firewalls
Virtual routers allow dynamic network reconfiguration
Virtual firewalls can protect servers
Useful for cases where installing a physical one would be hard, costly, or impossible
Note (p. 470): If you’re interested in reading more about virtual routers and firewalls, a couple of interesting product lines to look at are Brocade’s Vyatta vRouter and Cisco’s Cloud Services Routers.

45. Software Defined Networking (SDN)(1 of 2)
Traditional hardware routers and switches
A control plane makes decisions about how to move traffic
A data plane executes those decisions
SDN eliminates the control plane from individual devices and replaces with a programmable controller
Dictates how the entire network will behave

46. Software Defined Networking (SDN)(2 of 2)
Figure A controller controls traffic
to all the routers and switches

47. The Cloud

48. Figure 15.18 Amazon Web Services Management Console
To the Cloud
Figure Amazon Web Services Management Console

49. The Service-Layer Cake (1 of 2)
Software as a service applications are designed for end users
Delivered over the Web
End users generally interact with the software “icing” of the service-layer cake
Using Web applications such as Dropbox, Gmail, and Facebook

50. The Service-Layer Cake (2 of 2)
Figure A tasty three-layer cake

51. Infrastructure as a Service (IaaS) (1 of 3)
IaaS providers use virtualization to minimize idle hardware, protect against data loss and downtime, and respond to demand spikes
No longer need to purchase expensive, heavy hardware
Amazon Web Services (AWS) is one provider
Use requires OS knowledge and time to manage it

52. Infrastructure as a Service (IaaS) (2 of 3)
Figure Creating an instance on AWS EC2

53. Infrastructure as a Service (IaaS) (3 of 3)
Figure Amazon S3

54. Platform as a Service (PaaS) (1 of 2)
Provides a platform: all the software needed to run Web applications
No need to install or maintain software
Heroku: one of earliest PaaS providers
A simple interface reduces complexity of developing and scaling Web applications

55. Platform as a Service (PaaS) (2 of 2)
Figure Heroku’s management console

56. Software as a Service (SaaS)
Web applications serve up software
Monthly/yearly rate or for free
End users do not own the software
No need to regularly budget for upgrades
Users trade simplicity for loss of strict control of data
Relevant for intellectual property or business secrets

57. Cloud Delivery Models Types of cloud networks Public Private Community
Hybrid

58. Public and Private Clouds
Delivered through networks accessible by the general public
Private
Company develops an internal SaaS network, or outsources development of one

59. Community and Hybrid Clouds
Created by a group of organizations with similar needs
Hybrid
Some combination of public, private, and community clouds with connections between them
Services are integrated across the different types

60. Example: Use of a Hybrid Cloud
Mario’s drone-delivered lunch service
A private cloud to track orders and calculate routes
Third-party weather application in a public cloud
Flight-plan application to avoid other drones, helicopters, and aircraft in a community cloud