Understanding Limitations and Exclusions of Windows System Resource Manager
Applies To: Windows Server 2008 R2
The aim of Windows System Resource Manager is to ensure that system resources are available to processes, users, Remote Desktop Services sessions, or Internet Information Services (IIS) application pools (collectively called workloads). If unmanaged, these workloads can contend for and exhaust the system resources. However, there are situations in which Windows System Resource Manager is not an appropriate management solution or cannot guarantee sufficient resources to server workloads.
Windows System Resource Manager cannot manage system resources correctly if the computer is being managed by another resource manager, including process-oriented and job object-oriented resource managers. For best results, use Windows System Resource Manager as the only resource manager on the computer.
What should not be managed by Windows System Resource Manager
Applications with built-in resource management
Applications and processes that modify their process priority, memory limits, or processor affinity dynamically can interfere with the correct operation of Windows System Resource Manager.
If you use Windows System Resource Manager to manage a computer with applications that include built-in resource management, you must add the self-managed applications and processes, or include the particular resource the application is self-managing, to the user-defined exclusion list. For example, if a database server application is managing memory, Windows System Resource Manager can be used to manage the CPU but should not be used to manage memory for the application.
For more information about the user-defined exclusion list, see Work with the User-Defined Exclusion List.
Applications that use job objects
Some applications create processes that use job objects. Processes that use job objects cannot be managed by Windows System Resource Manager. To determine whether an application uses job objects, see the documentation for the application.
If you use Windows System Resource Manager to manage a computer with applications that use job objects, you must add those applications to the user-defined exclusion list.
What is not managed by Windows System Resource Manager
Applications or processes hosted by an excluded application
Exercise caution when adding processes that host other processes or applications to the user-defined exclusion list. If an application such as svchost.exe is added to the user-defined exclusion list, any process that it hosts could potentially consume all available resources because it is not managed. If the hosting process is not on the user-defined exclusion list, it and any processes it hosts will be managed as part of a criterion match or as part of the default group.
Resources used by the operating system
Processor and memory resources that are used by the operating system are excluded from management by Windows System Resource Manager. For example, if the operating system is using 25 percent of the available CPU on a system that is managed by the Equal_Per_User resource allocation policy, each of three users who are running processes on the computer will be allocated 25 percent of the total CPU, which is 33.33 percent of the CPU that is available to be managed.
If the remaining resources are not sufficient to support the workloads installed on the server, you can:
Reduce the number of workloads running on the server.
Install additional hardware to increase the available resources.
Install a Server Core installation of the Windows Server 2008 operating system to reduce the resources that are consumed by the operating system (if the applications and services running on the server support it).