Introduction to Virtualization
Transcript
5 in t days uh Microsoft actually bought that technology and integrated it into subsequent versions of Windows uh Windows nt40 had a terminal Services version and then after 2000 and later versions of Windows Server uh terminal Services came as a core part of the operating system that could just be added as a role since it's been out for an extremely long time there's extremely wide client support uh you can get thin clients there will that will run terminal service sessions as well as pdas smartphones uh all kinds of uh basically dumb devices have clients for terminal Services relatively simple implementation again it's very mature uh for Windows the most basic part parts of terminal Services you can a enable for uh versions of Windows 2003 to 2008 with very little trouble some of the disadvantages compared to other types of virtualization terminal Services is not as scalable there's also one of the reasons why it's not as scalable is because it uses a shared memory space so for every uh instance of your OS just because we have different user context doesn't mean that we have different uh memory pools so if you have applications that uh need their own set of or their own memory context or own memory containers or conflict with dlls or whatever the operating system conflicts are terminal Services has that disadvantage that you have still that shared memory pool and that shared OS kernel so that brings us to the other type of virtualization we'll talk about in this slide deck which is x86 space virtualization the hypervisor this is where we introduce the concept of the hypervisor with which adds a virtualization layer between the hardware and the operating system this picture from vmware's website gives us an example of how VMware approaches x86 virtualization the bottom half of our picture we have the CPU memory Nick and disc we have these physical components and when we put our hypervisor on top of those physical components when we install a hypervisor on that physical Hardware we can now create separate logical containers of CPU memory Nick and disc and then that could be presented to a operating system which then we can applications on so that problem of shared memory space shared single kernel for our guest operating system goes away with x86 virtualization I did want to take a few seconds to point out that there's a few different types of x86 virtualization there's full virtualization PA virtualization and Hardware assistant virtualization VMware uses a combination of full virtualization and Hardware assisted virtualization and in later classes we'll talk about some of the advantages that offers you as a user of VMware and other products that leverage hardware and full virtualization so hypervisors there's basically two types of hypervisors what's called a type one or bare metal hypervisor and a type two hypervisor which is considered a hosted hypervisor type 1 hypervisors examples of type 1 hypervisors are are VMware vpar and hyperv they're called type one hypervisors or bare metal hyper hypervisors because they're installed directly on your Hardware there's no overlying OS that that hypervisor needs to request resources from so uh esxi hyperv core Windows with just you're just installing the hyper V roll without the console are great examples of bare metal hypervisors obviously there's going to be a great performance ADV Advantage for bare metal Hy hypervisors when you don't have the overhead of another OS on top of that hypervisor so that brings us to the other type of hypervisor which is Type 2 hypervisor or commonly referred to as a Holsted hypervisor two examples of that are two extremely popular Solutions one is vmware's workstation and another one is virtual box both of those hypervisors require a host operating system in which to run under and an example of VMware Workstation we can install VMware Workstation in the Windows 7 Windows XP environment environment and we can install virtual box in basically a Windows XP Windows 7 environment and also both operating systems uh supported also include Linux and in the case of virtual box it supports uh OS 10 and VMware actually has a solution dedicated to um the Mac OS called uh VMware Fusion for a highlevel marketing overview of comparison of uh features for hypervisors I provided this link to vmware's website I'm not a big fan of of vendor specific comparisons because it's more marketing material but it's a good start on where to look at it difference in feature sets so this was again a very quick introduction to virtualization the different types future videos will walk you through actually installing a hypervisor uh in the case of our next hypervisor will V will VM workstation and actually installing a guest operating system in a hypervisor for more information on virtualization I provided these links as well as you can visit my website at www.
com
