Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272118AbTHNAYa (ORCPT ); Wed, 13 Aug 2003 20:24:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272121AbTHNAYa (ORCPT ); Wed, 13 Aug 2003 20:24:30 -0400 Received: from law14-f91.law14.hotmail.com ([64.4.21.91]:3844 "EHLO hotmail.com") by vger.kernel.org with ESMTP id S272118AbTHNAYW (ORCPT ); Wed, 13 Aug 2003 20:24:22 -0400 X-Originating-IP: [194.85.81.178] X-Originating-Email: [john_r_newbie@hotmail.com] From: "John Newbie" To: linux-kernel@vger.kernel.org Subject: ide drives performance issues, maybe related with buffer cache. Date: Thu, 14 Aug 2003 04:24:20 +0400 Mime-Version: 1.0 Content-Type: text/plain; format=flowed Message-ID: X-OriginalArrivalTime: 14 Aug 2003 00:24:21.0240 (UTC) FILETIME=[68148780:01C361FA] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1857 Lines: 44 Hi guys! Sorry for my post, but i didnt recieve answer on it after some googling & posting to local Linux Users Group, and i am confident that it is related with kernel. I am using linux quite long, tried (&tired of) many FS's on different hardware, and think this behavior is common. So question is : why when i am copying file from one HD to another (for simplicity from /hda to /hdb) the speed fall down ? Starting from about 27-30 MB/s (drives are in UDMA-4, hdparm -X68) it drops down to 11-12 MB/s after 4-5s. In *indows transfer rate is almost constant and about 20-22 MB/s (same hardware). Why the h#ll we suck? I feel that it's due to buffer cache, because when you use sync (while copying) transfer rate is so small or even 0. Drives are tuned with hdparm to highest transfer rates, readahead, multiple sector count (hdparm for details). Tried different filesystems, from classic ext2/3 to modern xfs/reiserfs. The same results. Pure kernel from kernel.org (2.4.{19,20,21}), vendors kernels - all the same. Doing experiments with 'sysctl -a |grep vm' values didnt resolve the problem. This behavior is general, i think. And, damn, this is very annoying for end users, for example when copying large files (movies,iso's). Beyond any doubt this is very bad for IDE based file servers. So please help me, and sorry if this post is offtopic. == Linux needs grouppies ! (inspired by Almost Famous & recent akpm interview) _________________________________________________________________ Help STOP SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/