Sorting Out “Desktop Virtualization”

Can you use Desktop Virtualization in your organization to improve IT delivery? Desktop Virtualization, as a concept, is straightforward – separate the desktop environment from the physical machine. This gives you benefits in terms of speed of delivery, how you can provide access to mobile and remote workers, how you can ensure security and compliance.

On the other hand – Desktop Virtualization, as a task,  is complex, it requires different technologies and practices to traditional desktop deployment. The task is further complicated because Desktop Virtualization, as a term, is applied to a variety of solutions. These include VDI (Virtual Desktop Infrastructure), HVD (Hosted Virtual Desktops), DaaS (Desktops as a Service), the use of Type 1 or Type 2 Hypervisors to create a “corporate sandbox” on an end-user workstation, and finally some new and enhanced desktop management techniques that deliver benefits of “Desktop Virtualization”, but without the data center server resource typically associated with this type of solution.

A number of vendors offer desktop virtualization solutions – how can you compare those offerings and relate them to what you need your desktop delivery strategy to do for your business?

With the above preamble in mind, we would like to propose the following categorizations and definitions of how desktops can be delivered to users.

  • Presentation Virtualization (PV): run multiple sessions on a server instance – typically on Microsoft’s  Remote Data Services (RDS), (formerly Terminal Services) (e.g. Citrix XenApp, Ericom PowerTerm Webconnect, Quest vWorkspace).
  • Server Hosted Virtual Desktops (SHVD): hosting a desktop operating system within a virtual machine running on a centralized server – also known as  Virtual Desktop Infrastructure (VDI)  (e.g., Citrix XenDesktop, VMware View)
  • Client Hosted Virtual Desktops (CHVD):  rather than run a virtual desktop on a server hypervisor, , run the hypervisor on the user’s device (e.g., MokaFive, RingCube, Citrix XenClient)
  • Physical Desktops (PDT):  PC’s, Laptops, with Windows XP, Windows 7 and installed applications

It is unlikely that one organisation will use a single delivery method from the list above. As we mentioned in our article, the Desktop Virtualization Iceberg – there are many components to a desktop virtualization project. The delivery of a desktop environment therefore needs methods to provide consistent access and allow you to maintain those environments. Vendors such as RES, Symantec, UniDesk and Wanova offer solutions to achieve this.

Who Delivers What

The table below breaks highlights which methods of workspace delivery vendors support, and then for the vendors that provide workspace management, which workspace delivery mechanisms are supported.

Vendor Solution
Workspace  Via
Manage Physical Desktops Manage Hosted Virtual
Manage Presentation
Client Hosted Virtual Desktops
2X App Delivery
PV, SHVD green check green check
Citrix App Delivery
PV, SHVD, CHVD,PDT green check green check green check green check
Double Take Desktop Deliver SHVD,PDT green check green check
Ericom App Delivery
PV, SHVD, green check green check
Kaviza Hosted Virtual Desktop SHVD green check
Microsoft PV, SHVD, CHVD,PDT

green check

green check green check green check
MokaFive Client Hosted Managed Desktop CHVD

green check

Pano Logic HVD Broker SHVD green check
RES Workspace
green check

green check

green check green check
RingCube Managed

green check

green check

Symantec Workspace
PV, SHVD, CHVD,PDT green check green check green check green check
App Delivery
PV,SHVD, CHVD green check

green check

green check
UniDesk HVD

green check

Virtual Bridges Hosted Virtual Desktop SHVD, CHVD green check green check
Client Hosted Virtual Desktop CHVD

green check

VMware Hosted

green check

green check
Wanova Desktop
SHVD, CHVD,PDT green check

green check

green check

While the above table gives an overview of who delivers what, it also depicts a confusing situation in terms of who manages what.  In almost all cases when a vendor provides delivery of a desktop via one of these mechanisms, that same vendor also provides for some management of that method of delivering a desktop.

However, there are many holes in the management solutions provided by the applications delivery vendors. UniDesk provides a level of layering and management for SHVD environments that is impressively rich and easy to use, but it is limited at the moment to just SHVD environments. CHVD vendors like Virtual Computer, MokaFive and Ringcube all provide for well managed environments , but as of yet cannot provide their management benefits to delivery mechanisms other than their own. This is probably because CHVD is new and as yet no de-facto standard has emerged for delivering the lower layers: and more importantly how those instances are synchronised with central copies.

The delivery of the desktop is not the only function you will need to consider in your enterprise desktop strategy. If you are using a variety of mechanisms, how are user’s application and workspace settings maintained between those environments? Locking down an environment can reduce support calls, but can come at a cost of decreased productivity and delay: how do you ensure that they have the correct privileges to manage their workspace effectively? User Virtualization Solutions – such as those from AppSense, RES and Scense can be used to compensate for the failings of Microsoft’s roaming profiles. Will deliver applications as part of the desktop, or will you separate those out with Application Virtualization solutions?


When considering where desktop virtualization can sit in your desktop strategy, be sure to consider what type of desktops will deliver workspaces for your users best. Our table above provides provides a summary of which vendors offer solutions to different delivery types.

Even after a decade of aggressively promoting and enhancing XenApp (and its former guises of MetaFrame and WinFrame), Citrix has never gotten above 15% penetration of enterprise desktops with its Presentation Virtualization (Terminal Services) based solution. Operating systems and applications physically installed on desktops and laptops represent the dominantly deployed method of software distribution and management for end user computing today. Server Hosted Virtual Desktops represent only a marginal improvement in desktop utility and management and suffer from almost every limitation that has held PV back over the years (with the requirement for persistent connectivity being at the top of the list). Indeed, in VDI TCO Analysis for Office Worker Environments Microsoft stated that with Windows XP SP3, SHVD (VDI) was 9% more expensive overall, and with Windows 7 VDI was 11% more expensive than solutions delivered with physical desktops.

The next generation of improvements in how desktops will be delivered and managed will come in the area of either improving the management of physical desktops that vendors such as  RES and Wanova are able to do, or in reinventing how client side desktops are delivered and managed as MokaFive, RingCube and Virtual Computer are focusing upon.

Leave a Reply

Be the First to Comment!