Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com Reply-To: Cygwin List Message-Id: <6.2.0.14.0.20050201144916.05a42210@pop.prospeed.net> Date: Tue, 01 Feb 2005 14:51:18 -0500 To: Ken Sheldon , cygwin AT cygwin DOT com From: Larry Hall Subject: Re: slow handling of large sets of files? In-Reply-To: <1107286130.3063.65.camel@slb163188094105.sugar-land.nam.sl b.com> References: <1107286130 DOT 3063 DOT 65 DOT camel AT slb163188094105 DOT sugar-land DOT nam DOT slb DOT com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" 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 -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/