On Thu, 26 Apr 2007, Bill Moran wrote:
I've seen marketing material that claims that modern NTFS doesn't suffer performance problems from fragmentation.
You're only reading half of the marketing material then. For a balanced picture, read the stuff generated by the companies that sell defragmenting tools. A good one to start with is http://files.diskeeper.com/pdf/HowFileFragmentationOccursonWindowsXP.pdf
Going back to the Jim's original question, they suggest a Microsoft paper that talks about how the defrag report can be misleading in respect to open files. See http://support.microsoft.com/kb/228198
Also, some of the most interesting details they gloss over are specific to which version of Windows you're using; the reference guide to the subject of how NTFS decides how much space to pre-allocate at a time is available at http://support.microsoft.com/kb/841551 (ZIP file wrapped into EXE, yuck!)
If you compare them, you can see that the approach they're using in NTFS has evolved to become more like that used by a good UNIX filesystem over time. I think your typical UNIX still has a healthy lead in this area, but the difference isn't as big as it used to be.
-- * Greg Smith gsmith@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD
