The key benefit of MED-V is that it helps enterprises deal with incompatibility between applications and the operating system. For instance, if a user needs to run an early version of Internet Explorer and that version of Internet Explorer is not supported on Windows Vista, the administrator can use MED-V 1.0 to deploy this early version of Internet Explorer to the user as part of a Windows XP virtual image. (And when MED-V 1.0 SP1 becomes available in Q1 of 2010, the user will be able to do the same thing on computers running Windows 7.) The user can then have two copies of Internet Explorer running simultaneously on his desktop—the most recent version (running on the host computer) and the earlier version (running in the MED-V workspace). From the user’s perspective, both copies of Internet Explorer appear as if they were running on the local computer. MED-V does this by allowing users to run legacy applications within a virtual machine that has an earlier version of Microsoft Windows installed. The user can then access these applications either from a virtual desktop (as with Virtual PC 2007 running natively on a system) or by using application windows that are seamlessly integrated into the local desktop of the user’s computer (similar to RemoteApp in Remote Desktop Services).
MED-V Usage Scenarios
The key usage scenario for MED-V is resolving application-to-operating system Incompatibility to accelerate the upgrade path to a new operating system. Businesses that need to continue to run legacy line-of-business applications on users’ desktop computers can do so by using Virtual PC. Incompatibility between legacy applications and newer versions of Microsoft Windows can often be a primary blocking issue preventing an enterprise from upgrading to the latest version of Windows, such as Windows Vista, to take advantage of the many new features and enhancements offered by this version. By delivering those applications in a Virtual PC that runs a previous version of the operating system (for example, Windows XP or Windows 2000), MED-V allows administrators to break the tight dependency between a computer’s underlying hardware and the operating system, and it can help remove such blocking issues so that your users can benefit from having the latest version of Windows deployed on their desktop computers. From the user’s perspective, with MED-V, these applications are accessible from the Start menu and appear side by side with regular applications—so there is minimal change to the user experience.
Microsoft Application Virtualization (App-V) also helps enterprises handle application compatibility issues, but it addresses challenges differently than MED-V does. Specifically, App-V lets you resolve conflicts that arise between different applications or different versions of the same application; MED-V, on the other hand, allows users to run older versions of Microsoft Windows concurrently with the local desktop of their computers, which can help with issues where legacy applications are unable to run natively on the most recent version of Windows installed on the user’s computer.
App-V Usage Scenarios
App-V supports a wide range of different usage scenarios, ranging from a full application virtualization infrastructure to a lightweight infrastructure to standalone deployment. Specifically, App-V supports the following usage scenarios:
- Full Infrastructure This scenario uses the App-V Management Server, which provides full streaming capabilities, Desktop Configuration Service, active/package upgrade, and basic licensing and metering. This infrastructure requires Active Directory and SQL Server and is an update to the existing SoftGrid Virtual Application Server that version 4.2 customers are familiar with using.
- Lightweight Infrastructure This scenario uses the App-V Streaming Server, which includes streaming capabilities such as active/package upgrade without the Active Directory or SQL Server requirements. However, it does not have a Desktop Configuration Service or licensing or metering capabilities. This service relies on the manual or scripted addition of a manifest file for virtual application configuration. The Desktop Configuration Service of the App-V Management Server can also be used in conjunction with the App-V Streaming Server such that the Management Server configures the application but the Streaming Server delivers it.
- Standalone mode The App-V Sequencer has an option to create an .msi file that automates the addition of the virtual application. The .msi contains metadata so that an ESD system can recognize it and control the virtualized applications. Standalone mode requires the App-V Client to go into Standalone mode, which allows only .msi-based updates of the virtual applications. (Streaming is not allowed while in Standalone mode.) This mode is meant for rarely connected users that need the power of virtualized applications but do not have access to a server.