From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751563AbWGPJid (ORCPT ); Sun, 16 Jul 2006 05:38:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751565AbWGPJid (ORCPT ); Sun, 16 Jul 2006 05:38:33 -0400 Received: from mail.gmx.de ([213.165.64.21]:21413 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S1751531AbWGPJid (ORCPT ); Sun, 16 Jul 2006 05:38:33 -0400 X-Authenticated: #5082238 Date: Sun, 16 Jul 2006 10:43:46 +0200 From: Carsten Otto To: linux-kernel@vger.kernel.org Subject: Re: Very poor IO performance (high CPU load), libata Message-ID: <20060716084346.GA6370@server.c-otto.de> Reply-To: c-otto@gmx.de Mail-Followup-To: linux-kernel@vger.kernel.org References: <20060715174555.GA27640@server.c-otto.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060715174555.GA27640@server.c-otto.de> X-GnuGP-Key: http://c-otto.de/pubkey.asc User-Agent: Mutt/1.5.11+cvs20060403 X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Problem solved! On Sat, Jul 15, 2006 at 07:45:57PM +0200, Carsten Otto wrote: > In the problem case the IO wait never drops below 40% no matter how light > the HDD load is. Logging in into the system via SSH then takes more than > two minutes and other tasks are equally slow. Okay, the wait percentage is no problem, but the speed is. I had to use a second power supply for two of the four SATA disks, because the main supply is not good enough and causes crashes and reboots (see my other threads, I will answer there too). In a test that checked each disk seperately I noticed that exactly those disks connected to the second power supply perform very poor with write accesses (65 MB/sec vs. 2 MB/sec). I replaced the second (bad) power supply with a very good one and now all disks are working fine. My new main power supply should arrive soon. I still can't understand why disks work slower when provided with "wrong" power... The disks are Maxtor MaXLine III 7V300F0. > There might be a problem with my hardware (in a not yet determined > device) causing this problem. But as long as I do not know what is wrong > I still see the chance of a software error in the kernel. Yeah, the kernel is okay :) PS: Now a very annoying hunt for some error in my computer ends after about three weeks. The system now is stable and fast and I am happy... Bye and sorry for bugging you, -- Carsten Otto c-otto@gmx.de www.c-otto.de