Microsoft KB Archive/314482

= How to configure paging files for optimization and recovery in Windows XP =

Article ID: 314482

Article Last Modified on 7/12/2007

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APPLIES TO


 * Microsoft Windows XP Home Edition
 * Microsoft Windows XP Professional

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This article was previously published under Q314482





For a Microsoft Windows NT and Windows 2000 version of this article, see 197379.



SUMMARY
The paging file (Pagefile.sys) is a hidden file on your computer's hard disk that Windows XP uses as if it were random access memory (RAM). The paging file and physical memory make up virtual memory. By default, Windows stores the paging file on the boot partition (the partition that contains the operating system and its support files). The default paging file size is equal to 1.5 times the total RAM. However, this default configuration may not be optimal in all cases. This article discusses how to configure the paging file for system optimization and recovery.

To enhance performance, it is good practice to put the paging file on a different partition and on a different physical hard disk drive. That way, Windows can handle multiple I/O requests more quickly. When the paging file is on the boot partition, Windows must perform disk reading and writing requests on both the system folder and the paging file. When the paging file is moved to a different partition, there is less competition between reading and writing requests.

However, if you remove the paging file from the boot partition, Windows cannot create a dump file (Memory.dmp) in which to write debugging information in the event that a kernel mode Stop Error message occurs. This could lead to extended downtime if you must debug to troubleshoot the Stop error message.

The optimal solution is to create one paging file that is stored on the boot partition, and then create one paging file on another partition that is less frequently accessed on a different physical hard disk if a different physical hard disk is available. Additionally, it is optimal to create the second paging file so that it exists on its own partition, with no data or operating-system-specific files. By design, Windows uses the paging file on the less frequently accessed partition over the paging file on the more heavily accessed boot partition. An internal algorithm is used to determine which paging file to use for virtual memory management.

When you put a paging file on its own partition, the paging file does not become fragmented, and this counts as another definite advantage. If a paging file resides on a partition that contains other data, it may experience fragmentation as it expands to satisfy the extra virtual memory that is required. An unfragmented paging file leads to faster virtual memory access and to a greater chance of a dump-file capture that is free of significant errors.

If you follow these recommendations, you meet the following paging file configuration goals for optimization and recovery:
 * The system is correctly configured to capture a Memory.dmp file if the computer experiences a kernel mode Stop Error.
 * The paging file on the less frequently accessed partition is used most frequently because it is on a partition that is least busy.



MORE INFORMATION
For additional information about how to move the paging file in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:

307886 How to move the paging file in Windows XP

For more information about how to set performance options in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:

308417 How to set performance options in Windows XP

For more information about how to configure recovery techniques in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:

307973 How to configure system failure and recovery options in Windows

Additional query words: page file multiple pagefile dump

Keywords: kbenv kbhowto kbinfo KB314482

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