What is User Virtualization?…
… In the past 18 months or so, the term “User Virtualization” has become more and more prevalent within the IT world. Even from just AppSense, this name is the associated with AppSense Software which is currently seeing annual revenues in excess of $70m. A significant sign of leadership in the space.. but does everyone truly understand what the term “User virtualization” means?
To put it into perspective, User Virtualization now has recognition with industry analysts, it is recommended by platform vendors such as Citrix, Microsoft and Cisco, and utilized in reference architecture by leading system integrators such as HP, IBM, Fujitsu and Dell and used by thousands of enterprise around the world… in essence, it is seen as the starting point, and the “glue” of desktop transformation. In other words, User Virtualization is a critical component and an enabler for organization keen to address their Desktop Transformation Strategy.
But not everyone truly understands and appreciates the true extent to what User Virtualization is, and hence there are vendors out there referencing themselves as User Virtualization vendors , when in actual fact they are not at all, or some journalists who do not understand the separation of the user from the desktop and the reasoning behind the name / term “User Virtualization”.
User Virtualization can be defined in two ways. In a very high level “fluffy” way, or the more technical (truthful) description and it is the high level message that can cause confusion in the market as vendor s may claim to be User Virtualization, however the technical description and capabilities is what clearly distinguishes one from another.
Before any of this, lets address the word which is causing this misconception, or lack of understanding, “Virtualization”.
What is Virtualization?
Virtualization in IT or technology terms describes, in my opinion, when something is being separated from the physical. It is the creation of a virtual instance of something (operating system, desktop session, application, storage device, network, or in this case – the user) and running this virtual instance separately as a decoupled occurrence on top of or in adjacent to other computing platforms.
So lets quickly look at some of the ‘Virtualization’ layers that can be part of our desktop build:
Operating System Virtualization:
So when a machine is virtualized, the Operating System is separated from the real hardware by a layer called the Hypervisor which enables to OS to now run as a virtual instance, running independently of the underlying hardware.
Application Virtualization:
In Application Virtualization, the areas where the application writes or reads from is separate from the real registry and file locations it would normally read or write to and from. In the case of Microsoft App-V, System Guard is the layer or bubble which facilitates this virtual instance of the applications, separate from the real file and registry.
So let’s get back to User Virtualization….
…The high level description that is being used in this area is being able to separate the user from the Desktop (Operating System and Applications), and allowing the user session to traverse across multiple Desktops, Operating Systems versions and application delivery methods, runs as a virtual instance on top of the underlying desktop components, separate from the desktop assets. This is (High Level) User Virtualization. – TRUE User Virtualization is being able to ensure that the user is truly separated from not only the Operating System, but also the Application. Not just managing an existing user (roaming) profile like some base/entry-level products do.
The reality, or more importantly the real technical definition is very similar to how I described Virtualization earlier, essentially you are separating something from interacting with its original physical locations – The settings for a user should be redirected from being read or written from their original physical registry, file and system locations to the virtualized area. Thus being separated from their original location and instead running in a virtual location, just how virtualization should be.
Are the users really virtual instances?
Now, with User Virtualization in place, when I change my window size for the application, colour or font size, or any other application setting, these changes should be redirected or detoured to a separate, virtual area, in the case of AppSense Environment Manager we call this area the Personal Virtual Cache (PVC).
The PVC is a virtual location separate from physical or underlying virtualized OS and/or Application components. All user read and writes are re-directed to this isolated virtual location with a user-level hypervisor. The PVC is synched centrally to the User Virtualization Platform database if there are any changes, ensuring the user remains separate from any desktop, at all times.
This then allows the Virtualized User to not only transcend the version of Operating System, whether it be Windows XP (Version 1 Profile) to Windows 7 (Version 2 Profile) but also whether the applications is delivered via local installation or virtual delivery (e.g. App-V etc). The same central settings applied to all delivery methods, without the user every actually touching or saving settings to the desktop, without having to logoff or back on!
Can everyone in the User Virtualization market provide True USer Virtualization?
If someone tells you they are doing User Virtualization, then challenge them. Ask to see their User Virtualization solution seamlessly capture and deploy user settings from one OS to another, and from locally installed applications to virtualized applications without the user having to logoff their session. Ask to see their virtualization layer, and make sure no trace of the user ever touch the underlying desktop.
User Settings should not be tied to specific delivery mechanism and should be managed and delivered within the user session, not a logon. Some vendors may say they support multiple delivery mechanisms, but scratch beneath the surface and you will find is that they can personalize both a locally installed application and the same application delivered by App-V, but not with the same user settings – there are two separate instances of the user settings, one for physical and one for virtual – you need to virtualize and share across both!
If they are allowing the application settings for a user to write and read to their original locations in the file and registry, and then somehow moving that file and registry information to a central storage repository based on a trigger like application close or logoff, then in my opinion this is a form of legacy or traditional ‘profile management’ utilizing out-dated registry hiving methodologies, NOT User Virtualization! All this is merely doing is reducing the chance of ‘Profile Corruption’ by reducing the window of opportunity for ‘Last Write Wins’ by saving portions of the users roaming profile back to the roaming profile central store throughout the user session instead of all of the profile at logoff. Such hiving / acceleration technologies are still subject to many of the other problems associated with Roaming Profiles such as bloat, inability to traverse across OS platforms or delivery mechanisms etc..
Also, if they are putting a roaming or local profile into a virtual disk and shipping it around the environment that way, I’m sorry that’s not User Virtualization, it’s not even Profile Management!
User Virtualization is more than Personalization
To us here at AppSense and our millions of end users, User Virtualization encompasses many things, not just separating the user settings from the Operating System and Applications, this is but a small part. User Virtualization must also look at dealing with such things as User Policy Management, User Rights Management, Application Entitlement, Network Access Control, Lockdown, Self-healing User Data Management, Lock-down, User Installed Applications, Self-Healing and even User QoS Performance
This is the true meaning of User Virtualization, to separate and manage all these aspects for the user, and only when we do this at every layer to enable complete separation of all desktop components that provides the ultimate flexibility in desktop management and delivery. And such flexibility can only be achieved by adopting a top-down approach. We are now moving to a user-centric world of computing, a world where we cannot continue to manage at the device or desktop level. Only by managing the user first, across all computing platforms can we adopt new technologies.
Just how big is User Virtualization?
With this in mind, User Virtualization is recognized by many as being potentially bigger than the VDI market itself. Time and time again we see organizations embrace AppSense / User Virtualization across their entire desktop estate; tens of thousands, or in some cases hundreds of thousands of users.. not just those select use cases that only every work purely in a VDI environment.
User Virtualization is game changing, it is going to be massive, please make sure you understand the capabilities and align this accordingly with your desktop strategy
Keen to hear your thoughts; what do you think?
Kristian Vidal – PreSales Manager, Northern Europe. AppSense.
Gareth Kitson – Director of Product Marketing, EMEA. AppSense.
Posted by Gareth Kitson 
AppSense 