Re: slow handling of large sets of files?

[Larry Hall <lh-no-personal-replies-please at cygwin dot com>]

At 02:28 PM 2/1/2005, you wrote:
>I too have been seeing a problem with very slow file access in large
>directories.
>
>Specifically,
>
>On a Cygwin/Win2k box, I have a mirror of an FTP site.  The site has 2.5
>million files spread between 100 directories.  
>(20,000 - 30,000 files per directory)  I have previously run this number
>of files in an NT4 NTFS filesystem without significant performance
>problems.
>
>In this site, operations like these are __VERY__ slow.
>ls ${some_dir}
>ls ${some_dir}/${some_path}
>cp ${some_file} ${some_path}
>cp -R ${some_path_with _only_a_few_files} ${some_path}
>
>
>If I look at the performance monitor, I can see a queue depth of 1-2 and
>300-500 disk reads per second.  (That's real.  It's a fast array)  The
>reads appear to be single-block reads, as the throughput during these
>events is 1.5 - 3MB/sec.
>
>I am beginning to think the disk activity relates to NTFS permission
>checking, which can be complex under Win2k.
>
>I don't know how to debug or tune this.
>
>Any ideas?


Have you looked at the '-x', '-X', and '-E' flags of mount?


--
Larry Hall                              http://www.rfk.com
RFK Partners, Inc.                      (508) 893-9779 - RFK Office
838 Washington Street                   (508) 893-9889 - FAX
Holliston, MA 01746                     


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