In this session, we’ll help those new to this area to understand the different types of virtualisation solutions available for both server and desktop.

1

In this session we’re going to cover what different types of virtualisation there are, and where they fit into the IT architecture.

Which combination is right for your organisation will depend on the problem you are trying to solve.

When virtualisation is mentioned, it is natural to think first of servers running many workloads. While this is indeed a popular approach, virtualisation can be used in many more ways.

Microsoft offers solutions for all the major areas for virtualisation in addition to server virtualisation:

• Presentation virtualisation (which you may know of as terminal services).

• Desktop virtualisation

• Application virtualisation

• User state virtualisation

2

Different elements of the computing stack interact through defined interfaces of either hardware or software. Whenever this happens there is a potential for contention and conflict. virtualisation can help to manage this and optimise performance.

By separating the different layers in the logic stack, you enable greater flexibility and simplified change management – you no longer need to configure each element for them to all work together. We’ve already talked about network, storage and machine virtualisation. But when it comes to PCs and notebooks, virtualisation is all about delivering user settings, applications and desktops when they’re needed.

The exact approach required will depend on user or business requirements, and a combination of all may be called for when looking to meet the needs of all the different users of IT services.

3

So far, we’ve looked at the main ingredients of virtualisation – how multiple operating systems can run virtually alongside eachother with high performance and few compatibility issues. Typically it’s this low level capability that springs to mind when people speak about virtualisation.

Even at this level, there are different approaches you can take when implementing and managing operating system virtualisation. The first approach is to run a small piece of software that’s a dedicated hypervisor (also commonly called a virtual machine manager). This is responsible for loading and booting all guest operating systems.

There are two types of hypervisors. The first type of hypervisor is termed Type 1 and is usually described as a “bare metal” hypervisor because it runs underneath the operating systems closely tied to the hardware. This is the hypervisor that is usedmost commonly for server virtualisation.

4

It is a common misconception that a Type 1 hypervisor has to be independent of any installed operating system.

While it is the case that many hypervisors are installed and managed independently, other Type 1 hypervisors are part of a stack themselves. They are configured and managed by a virtualised operating system installed together with, but which runs on top of, the hypervisor (as do all the guest operating systems).

A good example is Microsoft Hyper-V which can be a standalone hypervisor, but can also be installed with a management operating system alongside it to carry out the configuration and management of the virtual machine environment. (In this case, the management operating system, Windows Server 2008 R2, runs on top of Microsoft Hyper-V.)

5

When it comes to virtualisation, part of the aim is to operate guest operating systems totally unmodified so that they are able to just run. However, while this results in an ease of installation and compatibility, it can cause some problems when it comes to performance and overall capabilities.

Tackling this can require an approach called paravirtualisation. This recognises that for the operating system to perform well in a virtual environment, it helps if the guest is actually aware of the virtual environment and is modified to take advantage of it.

So instead of being presented with a default virtual environment, the guest can interrogate a hypervisor which is able to signalits capabilities. The guest operating system can then install the required software or drivers to take advantage of these features, enhancing performance in a virtual environment.

Taking this approach can sometimes result in dramatic gains, bringing performance much closer to the native level and enabling virtualisation to have a much broader level of applicability in the environment.

6

Virtualisation has a major role to play in how client-side IT – which has the widest scope in terms of use cases, deployment scenarios and application variety – is architected and delivered. In this scenario, IT looks to virtualise at many different layers to deliver greater usability, manageability and flexibility.

The essential rationale behind desktop virtualisation is to enable desktop environments to be controlled and managed from a central point. This facilitates such things as asset management and patch management, and enables policies to be defined and implemented more easily.

Desktop virtualisation can also mean greater flexibility for users by breaking the bond between physical technologies and theapplications that run on them. This means that, depending on the configuration, users can be free to run their own applications and data where it’s most convenient for them – for example:

• Logging on to whichever work computer is available, or even running their work environment on a home PC

• Running an application with specific configuration requirements, in parallel with other applications and operating systems without conflict

• Provisioning and allocating applications more flexibly from a central point, or indeed, allowing users to provision applications for themselves on a self-service basis

In addition, a number of security benefits also exist. Better control ensures user environments are as up to date (and thereforesecure) as possible. And this also offers the opportunity to better lock down what people do. Some desktop virtualisation variants also build in security features such as encryption of both data and network communications while permitting it to beheld centrally for enhanced protection.

Finally, virtualisation brings with it additional features such as the ability to take ‘snapshots’ of virtual machines.

Users in correctly configured virtual desktop environments have more options should something go wrong. For example, if a local desktop should fail, a user can access their work from another machine, as long as it has the correct access rights.

7

The term ‘thin client architecture’ refers to a specific computer configuration in which multiple desktop clients log on to a single instance of an operating system running on a single server.

Session virtualisation is an extension of this approach whereby all applications or the entire desktop run on a central server, with only the display graphics transmitted to the desktop client. A good example of this is Microsoft Terminal Services.

In session virtualisation, it is a good solution where you have a lot of users requiring similar desktop environments and the same applications that are each not too demanding. Once workloads ramp up, it can affect other uses and if different applications arerequired then compatibility issues can make deployments tricky.

Clients can either be thin client terminals, or else full PCs with a remote desktop or thin client application.

8

Where central, secure virtual desktops are needed, but session virtualisation cannot scale or offer enough flexibility, then Virtual Desktop Infrastructure may be appropriate:

Virtual Desktop Infrastructure (VDI) is a key technology for enabling successful desktop virtualisationimplementations – in all organizations, for network connected users. As a deployment model, VDI allows these users to access their personal desktops in the data centre. This may be from a thin client, so all computing happens in the data centre, or it can be from a full PC, in which case many applications can still run locally on the PC, but the secure or centralised applications are run from an application that provides a remote desktop link to the virtual desktop environment.

9

We saw one type of approach to running guest operating systems with Type 1 hypervisors, where all the operating systems installed run as virtual guests. There is another approach, and that is to have a native operating system, which has a hypervisor function built in or installed as an application.

This hypervisor runs alongside the native operating system and is responsible for launching and managing guest operating systems. This can be integrated into the operating system itself, or may involve a third party application. Depending on the solution, the hypervisor may be restricted in what operating systems are able to be installed and run.

Type 2 hypervisors evolved out of necessity due to the lack of hardware support. However, today they have a key role to play where a native host operating system is still desired but where you also want the added flexibility of running virtual guest operating systems.

10

11

Modern versions of the Type 2 hypervisor can take advantage of the new hardware features built into modern CPUs to support virtualisation. As a result, they are able to run with better performance and less impact on both the host and guest operating systems.

This also helps application compatibility as workarounds to problems such as kernel mode and user mode separation are handled more naturally. The host operating system manages a separate hypervisor that has hardware support. It means it no longer runs on top of the host operating system but more “alongside” it. This results in a hybrid approach where there is both aphysical host operating system and a hypervisor that run alongside each other.

Although Type 2 hypervisors were common for servers in the early days of x86 virtualisation, since hardware support has been added, most servers have moved to a Type 1 approach. However, when it comes to PCs and notebooks, the Type 2 - and now mainly hybrid - approach is still by far the preferred option, allowing test, development or demo environments to be set up easily without affecting the physically installed client operating system.

Traditionally, applications have been tied to the desktop operating system. They require installation on the client where they share resources such as runtime libraries and configuration settings.

In the application virtualisation model, individual applications are bundled up with the resources they need to run. Applications are not installed directly on the client computer, removing potential conflicts with other software and minimising the impact onthe operating system. This approach can also be combined with session virtualisation or VDI solutions for maximum flexibility inhow computing services and applications are delivered.

The application virtualisation and streaming is dependent on a special installation procedure called sequencing. This is able tounpackage and analyse the application, allowing it to be hosted on a streaming server and delivered in small chunks at a time for processing.

12

A growing number of organisations and IT vendors also describe user virtualisation, or sometimes even “user state virtualisation”.

In some scenarios a simple yet valid option is to ‘virtualise’ the link between a user’s configuration settings and data, storing this information on a server such that a user session can be accessed from any connected desktop client.

This works well in tandem with standardised desktop environments, where each desktop is running a similar set of applications. From the user perspective, not only can they log on where they want but, should something go wrong with the desktop, work can continue on another machine with minimal interruption.

13

In this track we’ve given an overview of the key areas for virtualisation within today’s business environment.

Which combination is right for your organisation will depend on the problem you are trying to solve.

Microsoft offers solutions for all the major areas for virtualisation:

• Application virtualisation

• Desktop virtualisation

• Presentation virtualisation (which you may know of as terminal services).

• User state virtualisation

• And, of course, server virtualisation

In this track we’ve given an overview of the key areas for virtualisation within today’s business environment.

All of these different pieces can play a role in your solution but what's critical is management. In a virtualised world, management becomes much, much more important. This is why System Center is placed as the focal piece of this slide.

Ultimately, success means taking a broad view from desktop to data centre to see where virtualisation can offer the most value to your business.

14

15

16

END