Page File Usage counter greater than 50%

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2009-12-08

The Microsoft® Exchange Server Analyzer Tool includes a performance data collection engine that is used to query performance counter objects on computers that are running Exchange 2000 Server or Exchange Server 2003. The performance data collection engine collects data from the % Usage counter of the Paging File performance object to analyze performance data.

If the Exchange Server Analyzer determines that the % Usage counter exceeded 50% during the sample time slice, the Exchange Server Analyzer displays an error.

The page file (Pagefile.sys) is a hidden system file on the hard disk that is used by Windows to store temporary data when your system is running low on RAM. The page file is also known as paging file or swap file. Page file use affects overall performance because disk operations take longer than memory operations. Also, when the paging to and from disk becomes high enough, a disk bottleneck eventually occurs and performance suffers. In this case, the real problem is memory, and the disk bottleneck is only a symptom.

Memory contention is tolerable until the system reaches a point where the system spends significant time managing the limited memory relative to the time that is required for the actual work. If you graph memory contention against average response times, you see a fairly smooth line from zero contention up to the point where response times increase significantly. This is referred to as the thrashing point. As memory contention increases past this point, response times increase exponentially. Temporary thrashing is tolerable in some environments, but you should work to avoid it.

This error indicates that there is a performance problem with the disk hosting the page file. This problem may ultimately be related to a memory issue on the server.

To resolve this error, take the following steps:

  • Consider locating the page file on a dedicated partition or high speed disk.

  • Remove superfluous software. To make more memory resources available for Exchange, remove any third-party software tools that perform monitoring functions or any kind of non-essential service. The Performance snap-in ( can help you understand how much memory applications are using.

  • Run server maintenance tasks during non-peak times. If you run maintenance tools, such as Exchange Server Database Utilities (Eseutil.exe), or tasks, such as mailbox management, during peak times, you can use memory that would otherwise be used by Exchange. As a best practice, run these tools and tasks during non-peak times or during low usage periods.

  • Consider moving user mailboxes from the affected server to another server to reduce server load. For more information, see Move User Mailboxes to Another Server.