BACKGROUND IMAGE: iSTOCK/GETTY IMAGES
What are UE-V, UPM, UPD, SCS and pending states, and how do these concepts impact App-V?
Endpoint application management remains an important challenge for enterprise administrators. Installation, patching and licensing can all pose problems, and businesses are turning to virtualized applications to improve and centralize application management. Tools like Microsoft App-V can abstract applications from the underlying operating system, allowing endpoints to use applications without ever installing the application locally. When used in concert with management platforms like System Center Configuration Manager, virtualized applications can be inventoried, patched and monitored from the data center. Let’s take a closer look at App-V and learn some basic concepts of the technology.
There are several concepts and acronyms related to Microsoft’s application virtualization platform that administrators should recognize when considering any App-V initiative.
Let’s start with user experience virtualization (UE-V), which is Microsoft’s tool designed to provide users with a consistent Windows experience regardless of the device being used. UE-V saves the paths and locations of user settings in an XML template. The XML template ensures that settings remain the same for a similar “look and feel” as users move from one Windows device to another. In essence, UE-V virtualizes the state of a user’s Windows environment -- decoupling settings from the particular system. Virtualizing the user experience (UX) is different than application virtualization, but UE-V and App-V can co-exist in the enterprise. For example, a user can move from one Windows machine to another with UE-V to provide an identical environment and App-V supplying the same virtualized application packages.
This newer notion of a “UX” is extremely close to the more traditional concept of a user profile which is so common in Windows operating systems from XP onward. A Windows profile basically contains objects and file system information in a hierarchy that defines all application settings and system configurations for individual users. It’s the user profile that makes sure Windows looks, feels, and acts the way you expect each time you log onto your computer (such as Internet Explorer settings, icon positions, desktop themes or wallpapers and so on). User profile management (UPM) is a broad term that describes the tools and techniques used to centrally store and organize user profiles from across the enterprise. It’s a necessary enabling technology for “roaming profiles”, which is the precursor to UE-V. If you’re not employing UE-V for profile management, you’re probably using a third party tool such as Immidio Flex+, TriCerat Inc.’s SimplyProfiles, or Citrix Systems Inc.’s UPM among others.
Remote desktop services (RDS) deployments may use roaming profiles and folder redirection to maintain user profiles, but organizations delving into UE-V and App-V are increasingly turning to a user profile disk (UPD) to retain settings and data between user sessions. A UPD is basically a virtual hard drive file that is streamed to a session host at logon. The image in the UPD supplies the personalized experience, and any changes to the profile are streamed back to the UPD at logoff. App-V generally does not rely on UPDs for user profiles, but UPDs can be handy tools for profile retention and management.
The shared content store (SCS) is a way of accessing virtualized application content without ever caching it on the local machine. Before SCS, older versions of App-V cached application content to the local system, which worked well but resulted in a great deal of content duplication across many enterprise user systems. SCS (when enabled in App-V 5.0 SP3) does not cache content locally. Instead, all content is streamed from centralized storage into the system’s memory. This effectively centralizes control of App-V packages, but can also place additional strain on central storage arrays. It’s important to stress test SCS performance and monitor it over time.
Finally, the concept of pending states is all about handling package changes over time. It’s unlikely that an application package will only be released once and never updated or patched. Instead, changes to a package’s components are an almost essential part of maintaining the application and managing its lifecycle. But it’s not practical to change a virtualized application while it’s running on a user’s computer. When a package is updated under App-V, pending state flags are used to signal that application changes are pending, and the updated package will be used when the service is restarted publish commands are used.
An expert guide to application virtualization
A look at the booming trend of UE-V
Improve your UX with these additional UPM tools