First up in this feature-by-feature rundown of what's new and exciting in Windows Server 2008 R2 is Terminal Services, er, Remote Desktop Services (RDS). Sporting a brand new name along with major new functionalities, RDS elevates Microsoft's venerable Terminal Services to a platform additionally capable of hosting your Virtual Desktop Infrastructure (VDI). Other hoped-for features are also available with the release of R2, but let's start with the most exciting first.
Remote Desktop Virtualization
The new Remote Desktop Virtualization (RDV) feature for RDS arrives first as an augmentation to the old Terminal Services Session Broker (TSSB) role service. In its original version, TSSB was responsible for load balancing users across multiple servers in a terminal server farm. This new version is now additionally responsible for brokering connections between users and hosted desktops running atop one or more Hyper-V servers.
This architecture, commonly called VDI or "hosted desktops," adds a second mechanism for connecting users to remote applications. With Remote Desktop Virtualization, users can be manually tagged to a specific personal desktop, or groups of available and similarly-configured desktops can be aggregated into "pools" for distribution as connections are made.
This concept of hosted desktops is not new technology. Vendors VMware, Citrix and others have been doing it for a while using their software and virtualization infrastructures. The difference here is a matter of cost versus functionality, as Microsoft's solution requires no additional costs outside of your Windows Server licenses to get started. At the same time, what you can do with Microsoft's administrative functionality may be comparatively limited.
Here's how the process works. An administrator first creates a set of hosted desktops within Microsoft Hyper-V. These desktops are either specifically tagged to a user or they become part of a pool for use by any connecting user. The use of clones in this case reduces the on-disk overhead of creating lots of virtual machines.
Once they are created, users can connect to available hosted desktops through any of the usual mechanisms first introduced in Windows Server 2008 RTM -- RDP file, local installation, Remote Desktop Web Access website and so on. As users connect, that connection first goes to the Remote Desktop Session Broker service to identify which hosted desktop should be provided. Once this information is known, the client's connection is redirected to the correct Hyper-V server to access the user's virtual machine. Just like with traditional Terminal Services applications, the network protocol, connecting user to machine remains RDP.
This new capability is a major play for organizations that still support problem applications, such as 16-bit apps or those that refuse to work with Terminal Services. Those who want to provide a fully-remote desktop for their users will also appreciate the integration. Users will see their hosted desktop alongside their traditional hosted applications either on their desktop or through Remote Desktop Web Access. The result is designed to look seamless to the user.
Fair share CPU scheduling
RDV is only one of the much-needed updates Windows Server 2008 R2 brings to the Terminal Services table. Another particularly impressive new feature is fair share CPU scheduling. Anyone who has seen the actions of one user spike the CPU resources on their terminal server -- and who hasn't? -- will appreciate how this feature works.
With fair share CPU scheduling, each user on a terminal server is given a percentage of CPU power equal to every other user on that server. For example, a server with 10 users will see each user getting approximately 10% of the overall power. This happens until the 11th user connects, when the balance is shifted again. If one user begins watching a video or running a developer build, or any other resource-intensive action, his or her individual session will show full utilization while the total server will only show utilization equal to the user's percentage. The result is a stunning reduction in resource overuse by your few problematic users.
RemoteApp and Desktop Connection
Another client piece that aligns Remote Desktop Services with what Citrix admins have used for years is RemoteApp and Desktop Connection. This feature is visually similar to the Citrix XenApp plugin, or what used to be called the Citrix Program Neighborhood Agent. With RemoteApp and Desktop Connection, Windows clients across your environment can be configured to look to a specific location on the network for the identification of available RemoteApp programs.
With RemoteApp and Desktop Connection, Windows clients across your environment can be configured to look to a specific location on the network for the identification of available RemoteApp programs.
Once discovered, RemoteApp programs are then made available automatically in the Start Menu or desktop of the client.
This operation is quite different from what was introduced in the RTM version of Windows Server 2008. There, to make RemoteApp programs available in this way, an MSI would first need to be created and subsequently installed to each client. The result was an added administrative overhead for "installed" RemoteApp programs requiring a software delivery mechanism like Configuration Manager or Group Policy for their deployment.
With RemoteApp and Desktop Connection, administrators need only to ensure that desktop clients are pointed to the correct discovery location. Clients will automatically check the location every few hours and update their list of applications.
Although it's a great new client add-on, the beta version does not support updating the local client's file extension associations when a new RemoteApp program is provisioned. Lacking this feature, users who try to access apps as RemoteApp programs won't be able to through the usual document invocation (i.e., double-click) method. Let's hope Microsoft adds this in the final version.
What else is new?
There are quite a few other RDS bonuses with Windows Server 2008 R2, although the remainder are
minor compared to the above three. Here's a list of some of the more interesting ones:
- Remote Desktop IP Virtualization. Some applications require that specific IP addresses are used on the server hosting the application. This is often the case because of licensing restrictions. Windows Server 2008 R2 adds the ability to virtualize -- or "spoof" -- IP addresses to enable these applications to function on Remote Desktop Services.
- Windows Installer becomes RDS aware. A major problem with traditional Terminal Services has long been related to the limitations of Windows Installer. In previous versions, Windows Installer wasn't fully aware of Terminal Services' multi-sessioning architecture, meaning it would not always correctly disseminate per-user customizations to new users. In Windows Server 2008 R2, Windows Installer is now RDS-aware, which means that the installation of most MSI applications should function with little post-installation hacking.
- Roaming profile cache management. If you allow roaming profiles to remain on your terminal servers, then you know how they can quickly fill up the available space. A new but small feature adds a bit of extra logic that removes the oldest profiles first when space gets tight.
- Ridiculously-powerful PowerShell integration. With the advent of Windows Server 2008 R2 comes the complete capability to manage RDS servers through Windows PowerShell. This includes the ability to view and modify configurations through the command line.
As before, many if not all of these features will require additional functionality at the client layer as well. With the release of Windows Server 2008 R2, you can also see the Remote Desktop Client updated to version 7. An install of this new version will be required to make use of most of the features discussed in this article.
This list isn't intended to be comprehensive for all of the new features. If you're interested in learning more about these features as well as others, check out Microsoft's document entitled What's New in Remote Desktop Services in Windows Server 2008 R2 Beta.
ABOUT THE AUTHOR
Greg Shields, Microsoft MVP, is a partner at Concentrated Technology. Get more of Greg's Jack-of-all-Trades tips and tricks at www.ConcentratedTech.com.
This was first published in April 2009