The pagefile is a critical component of the virtual memory system in Windows. However it can also become a critical bottleneck in the performance of Windows systems. Because it expands and contracts with the use of virtual memory, the pagefile is an especially active piece of disk space.
Windows normally puts the pagefile in the boot partition of the Windows disk. This makes sense from the standpoint of simplicity of layout, but it is not the best place for it. If the paging file shares disk space with other data it can become fragmented and since the paging file is used every time Windows accesses data from virtual memory, the fragmentation can cause a significant slowing of Windows response. If you want a faster Windows server, then having a fragmented pagefile is not in your best interests.
To preserve or improve performance, Microsoft recommends putting the pagefile in its own partition so it does not become fragmented.
Microsoft discusses this strategy in article # 318759#4 "How to Reduce Fragmentation by Moving the Paging File" in the Windows support database. See also article # 123747 "Moving the Windows Default Paging and Spool File" in the Microsoft Knowledge Base.
Rick Cook has been writing about mass storage since the days when the term meant an 80K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
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This was first published in April 2003