Client side virtualisation


To address the increasing cost and complexity of managing dynamic IT environments organisations are trying to understand how to adopt virtualisation technologies. The value proposition and “killer app” are quite clear in the data center, however less attention has been given to the opportunities for endpoint virtualisation.

Even though there are multiple methods to address client-side virtualisation; hosted virtual desktops (HVD), bare-metal hypervisors, local and streaming virtual workspaces and a range of options that layer on top of and between them all, such as application virtualisation, portable personalities, and virtual composite desktops, there is still a tremendous amount of confusion and even more misconceptions about the benefits of client-side virtualisation than with server virtualisation.

The major architectural flaw in almost all of these solutions is they remain very back end and infrastructural heavy, which reduces the benefit of cost-reduction and lower complexity.

Let’s look at the 3 client-side virtualisation models I believe will become the most prevalent over the next 3-5 years…

Application virtualisation

The concept is fairly straight forward, using a packaging technology an organisation develops a virtual application, this can be done by diffing a gold-image pre and post install of an application, in which the virtual “container” includes all elements of the application, including emulated registry settings, file system calls, etc.

The benefits centre on software distribution, perceived licensing and software asset management cost reduction and improved application compatibility.

Workspace/Desktop virtualisation

Extending the concept of application virtualisation to an entire desktop or workspace. Users will enjoy multiple applications, user/system/security settings and other aspects of their workspace provided through a virtual container.

The virtual container, in some cases, isolated from the non-virtual workspace will enable IT to secure a corporate workspace and allow a user workspace to be less secure, or more importantly isolated from the more secure and critical corporate workspace.

All virtualisation still occurs within an existing OS and doesn’t negate the need to properly maintain the health and security of the original computing platform, however additional people, process and technology will be required to also support the virtual / desktop workspace environment as well.

PC Client Infrastructure virtualisation

The reality of hosted virtualisation solutions, and in this case I am using the term hosted to refer to virtualisation technologies that are provided within an existing OS. Application virtualisation is a virtual application delivered to and run within an existing OS environment, although from within a virtual container.

Desktop and workspace virtualisation is a virtual desktop/workspace delivered to and run within an existing OS although from within a virtual container.

In both cases the virtual environments rely on the operating system to provide and coordinate shared hardware resources and both are at the mercy of operational failures and system compromises for availability.

There is no question they provide benefit, however if we can move to a virtual infrastructure with virtual machines delivered to a desktop we could provide an abstraction layer between the hardware and the various virtual machines and more importantly abstraction from the virtual machines and the operating system itself.

The Problem With Current VDI Architectures

Virtual Desktop Infrastructures (VDI) promise to radically change systems and security management at lower cost and better efficiency then is possible with current technologies. Show of hands – who would like to do more with less?

Although the vendors will claim increased performance, improved security and more effective management the reality is that the infrastructural costs of deploying virtual desktops can be significant, in many cases it would require a complete infrastructural overhaul or a move to thin-clients and it would require us to accept that we can no longer support or in some cases allow remote, mobile computers.

Hosted virtual desktops, thin-client computing models, centralising desktop management into a datacenter and solutions that require heavy back-end infrastructure and perfect implementations of Active Directory are doomed to fail.

So tread carefully when a C-level exec or overzealous IT administrator returning from a boondoggle weekend with VMWare returns proclaiming the end of the traditional desktop is here and VDI offers nigh-invincible security and systems management attributes.

The model for server virtualisation is all about consolidation and centralisation, and it has shown tremendous benefit although there are still many myths, misconceptions, and half-truths about virtualisation but the reality is that we are moving to a more globally distributed computing model with many remote, intermittently connected computing devices.

These have the ability to not only access corporate resources located within the corporate HQ, but also corporate applications hosted by a 3rd party or delivered as a service from a 3rd party.

Bottom Line: In some select situations client-side virtualisation does hold promise for improved efficiencies, lower cost and improved security and systems management.

It has benefits for software distribution and OS deployment models, but until the industry understands that we will not return to thin-client computing models and centralised management is antithetical to every current trend in client computing we will not see widespread adoption of VDI no matter what VDI vendors claim.