Tech Talk 8 by Jason Blackett
A Deep Dive into ZENworks Application Virtualization 7.1
The Full mode only allows the application to read or write files to the virtual file system. If you set My Documents to Full, then the user would only see the contents of the My Documents folder in the virtual application’s sandbox. The sandbox is an isolated area in the virtual environment for storing user-defined settings and files. Additionally, the application would write all of the user’s saved files to the sandbox. The Full mode is especially useful if you want the virtual application to run on a USB thumb drive and you want to make sure that the user's documents are only saved on the thumb drive.
The Write Copy mode allows the application to read from the host, but it always writes any changes to the sandbox. This mode is useful when a file or files are needed from the host machine, but you want to make sure the virtual application cannot impact the host.
The Merge and Full options can also be used for isolating registry settings. In other words, you can control whether the application has access to registry keys not included in the sandbox.
In addition to letting you create virtual applications, ZENworks Application Virtualization also allows you to build a virtual set of self-contained components called an XLayer. An XLayer would be comprised of various files, registry entries or other components that a certain application might require, such as your browser needing a certain version of Java. When you create an XLayer it can be dynamically used by a virtual application or can be embedded into an application. Building an XLayer file simply requires you to change the Project Type in the solution’s interface to Component instead of Application.
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A typical usage for an XLayer would be to create a reusable set of self-contained virtual components that can be leveraged by multiple virtual applications. For example, the prebuilt run times available in ZENworks Application Virtualization (i.e., .NET Framework, Flash Player and the Java Runtime Environment) can be injected into a virtual application at build time. To do this you simply click the button in the toolbar that represents the component you want to inject and it will embed the component when it builds the virtual application. By embedding these required components into the virtual application you only have to distribute a single executable file, rather than all the other applications or files it depends on for proper execution.
Another common use case for XLayers is patching your virtual applications. Since virtual applications run in an isolated environment, they generally can’t be patched using traditional self-updating methods. Rather than re-creating an entirely new patched version of the virtual application, you can create an XLayer that contains the patched information. This file can then be distributed to your user machines and placed in the same directory as the parent virtual application. By doing this, the next time the application launches, the application will dynamically load the contents of the XLayer file, patching the application. To create an XLayer patch file, you install the baseline application on your build machine and then use the snapshot mode to capture the patch information as you apply the patch to the application.
XLayer files can also be used for common application plug-ins, such as Microsoft Silverlight or Adobe Reader for your Web browser. Without the ability to use XLayers for your plug-in components, you would have to create different versions of the same virtual application, each containing the different plug-ins your different users need. Instead, by building your plug-ins as virtual components, you can create a single baseline version of the virtual application and place its associated plug-in XLayer files as needed on user machines in the directory where the application resides. This allows the plug-ins to be automatically loaded the next time the application launches.
Whether you use its basic or advanced configuration features, ZENworks Application Virtualization gives you the ability to create custom and secure virtual applications that eliminate the traditional overhead of managing Windows applications. ZENworks Application Virtualization also enables you to simplify and accelerate application rollouts, while reducing downtime and helpdesk calls, and providing you greater application portability, flexibility and interoperability.