Remote Desktop Session Host
Updated: June 12, 2009
Applies To: Windows Server 2008 R2
The Remote Desktop Session Host (RD Session Host) role service, formerly the Terminal Server role service, has been enhanced in Windows Server 2008 R2. The following changes are available in Windows Server 2008 R2:
The improvements to the RD Session Host role service will be of interest to organizations that currently use or are interested in Remote Desktop Services.
You may also be interested in these improvements in the RD Session Host role service if you want to support any of the following scenarios:
Your organization has programs running on an RD Session Host server that require IP addresses to be assigned on either a per session or per program basis.
Remote desktop users within your organization routinely install programs within their RD Session Host session.
The new functionality provided by these new features in the RD Session Host role service is described in the following sections.
The client experience configuration page is available when installing the RD Session Host role service by using Server Manager. The client experience configuration page allows you to configure the following functionality:
Audio and video playback redirection. Audio and video playback redirection allows users to redirect the audio and video output of a local computer to an RD Session Host session.
Audio recording redirection. Audio recording redirection allows users to redirect the output of an audio recording device, such as a microphone, from the local computer to an RD Session Host session.
Desktop composition. Desktop composition provides users with the user interface elements of the Windows® Aero® desktop experience within their RD Session Host session.
|Configuring any of these features also installs the Desktop Experience role service and starts the Windows Audio service on the RD Session Host server.|
This page centralizes the client experience configuration into Server Manager.
To take advantage of the new client experience features, the client must be running Remote Desktop Connection (RDC) 7.0.
In Remote Desktop Services in Windows Server 2008 R2, you can filter the list of RemoteApp programs that are available to a user account when logged on to RD Web Access.
Prior to Windows Server 2008 R2, all RemoteApp programs were shown to every user that logged on to RD Web Access, regardless of whether they had access to run the program.
Fair Share CPU Scheduling is a new feature included with Remote Desktop Services in Windows Server 2008 R2. Fair Share CPU Scheduling dynamically distributes processor time across sessions based on the number of active sessions and load on those sessions by using the kernel-level scheduling mechanism included with Windows Server 2008 R2. On an RD Session Host server, one user will not affect the performance of another user's session, even if the RD Session Host server is under a high load.
Fair Share CPU Scheduling is enabled by default. You can disable this feature by configuring the following registry entry to 0: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\SessionManager\DFSS\EnableDFSS.
Prior to Windows Server 2008 R2, the Windows scheduler provided a fair scheduling policy by distributing the processor time evenly across all threads at a given priority level. Priority could be adjusted by using management software to give one thread preference over another. In an environment with multiple users, this scheduling policy provided a good way to throttle any one user from completely monopolizing the CPU, but was unable to evenly distribute the processor time in the presence of dynamic loads.
Windows Installer RDS Compatibility is a new feature included with Remote Desktop Services in Windows Server 2008 R2. With Remote Desktop Services in Windows Server 2008 R2, per user application installations are queued by the RD Session Host server and then handled by the Windows Installer.
In Windows Server 2008 R2 you can install a program on the RD Session Host server just like you would install the program on a local desktop. Ensure, however, that you install the program for all users and that all components of the program are installed locally on the RD Session Host server .
Windows Installer RDS Compatibility is enabled by default. You can disable this feature by configuring the following registry entry to 0: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows NT\Terminal Services\TSAppSrv\TSMSI\Enable.
Prior to Remote Desktop Services in Windows Server 2008 R2, only one Windows Installer installation was supported at a time. For applications that required per user configurations, such as Microsoft Office Word, an administrator needed to pre-install the application, and application developers would need to test these applications on both the remote desktop client and the RD Session Host server. Windows Installer RDS Compatibility queues the installation requests and processes them one at a time.
A new Group Policy setting is available for Remote Desktop Services in Windows Server 2008 R2 that limits the size of the overall profile cache. If the size of the profile cache exceeds the configured size, Remote Desktop Services deletes the least recently used profiles until the overall cache goes below the quota.
You can configure the maximum size of the roaming user profile cache on an RD Session Host server by applying the Limit the size of the entire roaming user profile cache Group Policy setting. The Group Policy setting is located in Computer Configuration\Policies\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Profiles. If you enable this policy setting, you must specify a monitoring interval (in minutes) and a maximum size (in gigabytes) for the entire roaming user profile cache. The monitoring interval determines how often the size of the roaming user profile cache is checked.
|If you are using the Local Group Policy Editor, "Policies" is not part of the node path.|
A Remote Desktop Services environment can potentially have hundreds of distinct users. Whereas caching of roaming user profiles is enabled for better end-user experience, this profile cache can grow very large and may potentially overrun the available disk space on the server.
Remote Desktop IP Virtualization allows IP addresses to be assigned to remote desktop connections on a per session or per program basis. Remote Desktop IP Virtualization is configured on the RD IP Virtualization tab of the Remote Desktop Session Host Configuration tool.
If you assign IP addresses for multiple programs, they will share a session IP address. If you have more than one network adapter on the computer, you must also choose one network adapter for Remote Desktop IP Virtualization.
Some programs require that each instance of the application be assigned a unique IP address. Prior to Windows Server 2008 R2, all sessions on an RD Session Host server shared the IP address assigned to the RD Session Host server. With Windows Server 2008 R2, you specify a network ID that Remote Desktop IP Virtualization uses to assign IP addresses on a per session or per program basis.
RD Session Host is available in the following editions of Windows Server 2008 R2:
Windows Server 2008 R2 Standard
Windows Server 2008 R2 Enterprise
Windows Server 2008 R2 Datacenter
RD Session Host is not available in the following editions of Windows Server 2008 R2:
Windows Web Server 2008 R2
Windows Server 2008 R2 for Itanium-Based Systems