From owner-freebsd-stable@FreeBSD.ORG Mon Mar 26 18:36:38 2007 Return-Path: X-Original-To: stable@freebsd.org Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id F3F1A16A401 for ; Mon, 26 Mar 2007 18:36:37 +0000 (UTC) (envelope-from mi+kde@aldan.algebra.com) Received: from mail7.sea5.speakeasy.net (mail7.sea5.speakeasy.net [69.17.117.9]) by mx1.freebsd.org (Postfix) with ESMTP id C72B913C4AD for ; Mon, 26 Mar 2007 18:36:37 +0000 (UTC) (envelope-from mi+kde@aldan.algebra.com) Received: (qmail 7732 invoked from network); 26 Mar 2007 18:36:37 -0000 Received: from aldan.algebra.com ([216.254.65.224]) (envelope-sender ) by mail7.sea5.speakeasy.net (qmail-ldap-1.03) with AES256-SHA encrypted SMTP for ; 26 Mar 2007 18:36:36 -0000 Received: from aldan.algebra.com (aldan [127.0.0.1]) by aldan.algebra.com (8.13.8/8.13.8) with ESMTP id l2QIaUCJ046130 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 26 Mar 2007 14:36:30 -0400 (EDT) (envelope-from mi+kde@aldan.algebra.com) Received: from localhost (localhost [[UNIX: localhost]]) by aldan.algebra.com (8.13.8/8.13.8/Submit) id l2QIaSI9046129; Mon, 26 Mar 2007 14:36:28 -0400 (EDT) (envelope-from mi+kde@aldan.algebra.com) From: Mikhail Teterin To: =?iso-8859-1?q?S=F8ren_Schmidt?= Date: Mon, 26 Mar 2007 14:36:27 -0400 User-Agent: KMail/1.9.5 References: <200603010505.k2155HfQ003205@aldan.algebra.com> <44054C5E.5070902@deepcore.dk> <200603011107.09942@aldan> In-Reply-To: <200603011107.09942@aldan> X-Face: %UW#n0|w>ydeGt/b@1-.UFP=K^~-:0f#O:D7whJ5G_<5143Bb3kOIs9XpX+"V+~$adGP:J|SLieM31VIhqXeLBli" Cc: Dmitry Pryanishnikov , stable@freebsd.org, Derek Ragona , Brian Candler Subject: Re: pitiful performance of an SATA150 drive X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Mar 2007 18:36:38 -0000 Over a year later this remains a problem -- exactly as described below... No other SATA devices are present -- the only other IDE device is the DVD drive. My main disks are SCSI. What's MUCH worse is that the (slowly) written data is also often corrupted... I use the drive to store our vast collection of photos and the backups. Every once in a while I encounter a corrupt JPEG file, and the backups are _always_ corrupt somewhere. Doing something like: dump 0auChf 16 0 - /home | bzip2 -9 > /store/home.0.bz2 always produces a corrupt file (as per ``bzip2 -t''). I used to blame the drive's temperature, but it now sits in its own enclosure and stays under 40 Celsius. When the drive is accessed, there are (according to `systat -vm') many thousands of interrupts 17 -- on my system these are shared between pcm0 and ehci0. Why are these triggered by accessing SATA is unclear, but the Intr's share of the CPU time is often above 80% of one processor's total (I have 4 processors). As I mentioned a year ago, Knoppix was accessing the same drive at much higher speeds, so I don't believe, the problem is with the hardware... Please, advise. Thanks! -mi On Wednesday 01 March 2006 11:07, Mikhail Teterin wrote: = On Wednesday 01 March 2006, Søren Schmidt wrote: = = dd if=/dev/ad8 of=/dev/null bs=1m = = Well, as I said, there is no obvious problems with _reading_. The above = command reads at well over 60Mb/s: = = 1638924288 bytes transferred in 25.374856 secs (64588516 bytes/sec) = = _Writing_, however, remains pathetic: = = dd of=/dev/ad8 if=/dev/zero bs=1m = 631242752 bytes transferred in 91.039066 secs (6933757 bytes/sec) = = = The problem is the blocksize that gets in the way of utilizing full = = transfer speed. = = Did you really expect the blocksize to make an order of (decimal) magnitude = difference? :-) It made no difference at all :-( = = Brian Candler asked: = = Just to be clear: this is Knoppix running on the *same* machine as you've = = been testing FreeBSD? = = Correct. = = = Aside: why are you using cat under FreeBSD, but dd under Knoppix? I'd use dd = = everywhere for consistency. = = Cat was slightly faster in my tests on FreeBSD. I used dd under Knoppix for = dd's throughput reporting -- I'm not aware of a monitoring tool like `systat' = under Linux. = = Yours, = = -mi =