Introduction
In this article, you will learn about Microsoft Desktop Enterprise Virtualization (MED-V), Microsoft’s solution for a local desktop virtualization with centralized management. Using MED-V, you can deliver multiple virtual machines to execute on end-user desktops while retaining policy-based control over virtual machine configuration, provisioning, and availability.
Desktop Virtualization Strategy: Central or Local?
While server virtualization is primarily about consolidating and centralizing the workloads of physical machines on a smaller number of more powerful servers, there are two main strategies to consider for desktop virtualization. If an organization has the goal to virtualize desktop workloads onto centralized data center servers, desktop virtualization can be accomplished through the implementation of a Virtual Desktop Infrastructure (VDI). Virtual desktops are accessed using rich or thin client devices that support a remote desktop application such as Microsoft RDP for connection. The benefits of a VDI strategy are:
Support for personal (dedicated) or pooled (shared) virtual desktops
Support for mobile or roaming users on a variety of client devices
Enhanced control over the desktop environment and user data storage
Enhanced desktop environment business continuity solutions
Now consider the scenario of an organization that wants to migrate physical machines to the Windows 7 client operating system to take advantage of its new feature set, but has one or more groups of users that need access to legacy applications that are compatible only with older Windows clients such as Windows XP. In addition, users must access new and legacy applications through a single common interface to maximize usability and minimize user training requirements. There are multiple solutions to satisfy these requirements, including Remote Desktop Services (RDS) with Remote App. However, if an organization has not deployed an RDS infrastructure, a local desktop virtualization strategy is another option. This strategy includes the deployment of a hosted virtualization application to a physical desktop, providing local access and execution of multiple workloads (operating system and application stack) running in distinct virtual machines (VM) with a seamless desktop user experience. MED-V is the Virtual PC 2007 based Microsoft solution that allows implementation of this type of local desktop virtualization strategy. The benefits of a MED-V strategy are:
Support to deploy Virtual PC 2007 VMs to Windows Vista or Windows 7
Support of a centralized repository for VM storage, versioning, and delivery
Support for bandwidth-conservation during delivery and update of VMs
- Support for Active Directory integration to control VM provisioning and access
In summary, VDI and MED-V provide solutions at opposite ends of the virtualization spectrum. Within a Microsoft centric solution, VDI uses Hyper-V as a platform to provide a centralized strategy for desktop virtualization, whereas MED-V uses Virtual PC 2007 as a platform to provide a localized strategy for desktop virtualization with centralized management.
MED-V Availability
If you browsed the Microsoft product list, you might be confused as you will not find MED-V in it. Microsoft provides MED-V as part of the Microsoft Deployment Optimization Pack (MDOP) for Software Assurance. Microsoft Software Assurance is a volume licensing maintenance offering that includes software updates, services, training, and tools. If you are interested in learning more about MDOP, refer to the MDOP site.
MED-V v1 Terminology
Before exploring the MED-V architecture, it is important to understand the terminology that is used with this solution. The following terms are of particular importance:
- Image – A virtual machine in which an operating system and applications are installed
- Usage Policy – A collection of settings that define the user or group assignment, user interface, usage restriction, image configuration, and application association
- Workspace – A combination of an image and usage policy
- Seamless Mode – A functionality that allows an application running in a VM to present as an application running on the physical desktop operating system
In seamless mode, a user can be unaware that a virtual machine is used to host applications that are incompatible with the operating system installed on the physical desktop. Applications are available to users through the standard desktop Start Menu and are launched just like the applications that are natively installed on the desktop operating system.
MED-V v1 Architecture
MED-V includes several components that combine together to provide a solution to manage the creation, testing, provisioning, maintenance, and troubleshooting of virtual machines from a central location. The main MED-V components include:
- MED-V Management Server
- MED-V Management Console
- MED-V Image Repository Server
- MED-V Client
- Virtual PC 2007
MED-V Management Server
The MED-V management server provides the centralized management of VMs stored in the MED-V image repository and deployed VMs. It also maintains the mappings between VMs, usage policies, and the Active Directory (AD) users and groups to which they are assigned. Using Active Directory Domain Services (ADDS), the MED-V management server enables provisioning of VMs based on user or group membership, as well as enabling user authentication prior to VM access. MED-V clients also connect to the MED-V management server to authenticate and retrieve up-to-date usage policy.
In addition, the MED-V management server enables aggregation of client events that it maintains in an external SQL Server, and that are used to monitor and report on client status.
MED-V Management Console
The MED-V management console is the graphical user interface (GUI) through which administrators gain access and interact with the MED-V management server and MED-V image repository. The MED-V management console enables administrators to update usage policies, provision MED-V workspaces to users and de-provision existing users, as well as create, manage, update, or delete images stored in the MED-V image repository. Image updates are automatically distributed to relevant users when they work online.
MED-V Image Repository Server
The MED-V image repository server is an IIS Server which stores VMs and enables VM versioning, as well as VM retrieval and distribution using Trim Transfer technology. Trim Transfer technology provides a mechanism to eliminate the transfer of data that is identical between the VM image and the destination desktop. In addition, when an updated VM image is delivered, only the data that has changed will be transferred to the destination desktop.
MED-V Client
The MED-V client component is installed on the desktop client machines. The MED-V client is used to connect and authenticate to the MED-V management server, which in turn queries AD for access control and security policy settings. Following completion of the authentication process, the MED-V client retrieves up-to-date usage policy from the MED-V management server and retrieves VM image data from the MED-V image repository. The MED-V client is also responsible to customize the VM based on policy, as well as initiating, suspending and terminating a VM session within the Virtual PC 2007 environment.
Virtual PC 2007 SP1
Virtual machines provisioned to a MED-V client run in Virtual PC 2007 SP1 (and requires the hotfix rollup package contained in KB958162). Virtual PC 2007 SP1 is a hosted virtualization platform that runs on top of a defined set of Windows operating systems, providing support for 32-bit guest VMs.
Virtual PC 2007 SP1 also supports hardware-assisted virtualization, but does not require it. Hardware-assisted virtualization is configurable on an individual VM basis. Virtual PC 2007 SP1 is a free download available on the Microsoft website.
MED-V v1 System Requirements
MED-V v1 provides support for client desktops running 32-bit Windows XP SP2 and SP3, and 32-bit Windows Vista SP1 and SP2. It supports VM images based on Windows XP Pro SP2 and SP3, as well as Windows 2000 SP4. The MED-V management components support installation on Windows Server 2008.
MED-V v1 SP1 is currently in the Release Candidate phase and planned for release in April 2010. With MED-V v1 SP1, Microsoft adds client desktop support for 32-bit and 64-bit Windows 7.
Conclusion
If your organization has a requirement to deploy Windows 7, but still has legacy applications that run on Windows XP and there is no RDS or virtualization infrastructure to leverage, MED-V v1 SP1 is a local desktop virtualization solution that can help you meet your desktop operating system upgrade objectives. Available as part of the MDOP for Software Assurance, MED-V v1 SP1 provides a virtual machine provisioning and management environment for client desktops, with limited additional infrastructure requirements, and with a seamless desktop experience for end users.
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