From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 21 Sep 2001 04:10:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 21 Sep 2001 04:09:57 -0400 Received: from h24-64-71-161.cg.shawcable.net ([24.64.71.161]:17918 "EHLO webber.adilger.int") by vger.kernel.org with ESMTP id ; Fri, 21 Sep 2001 04:09:53 -0400 From: Andreas Dilger Date: Fri, 21 Sep 2001 02:09:38 -0600 To: David Hajek Cc: linux-kernel@vger.kernel.org Subject: Re: high cpu load with sw raid1 Message-ID: <20010921020938.I14526@turbolinux.com> Mail-Followup-To: David Hajek , linux-kernel@vger.kernel.org In-Reply-To: <20010920102616.A2753@pida.ulita.cz> <20010920124020.D14526@turbolinux.com> <20010921090720.A12970@pida.ulita.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20010921090720.A12970@pida.ulita.cz> User-Agent: Mutt/1.3.20i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sep 21, 2001 09:07 +0200, David Hajek wrote: > On Thu, Sep 20, 2001, Andreas Dilger wrote: > > On Sep 20, 2001 10:26 +0200, David Hajek wrote: > > > I have linux box with 70GB SW Raid1. This box runs for half > > > a year without problems but now I meet the high cpu load > > > problems. I suspect that it can be caused by not enough > > > free disk space on this md device. I see following: > > > > > > 1 GB free - load > 5 > > > 5 GB free - load < 1 > > > > What filesystem are you using? If it is reiserfs, and you have < 10% > > of the disk free, it is very unhappy. A patch to fix this is available. > > I'm using ext2. I suspect high ext2 fragmentation, because when > there are 'only' 1GB free the disk is _really_ busy. I doubt > that it takes lot of time to find free blocks. OK, I just re-read your initial posting, and see you have a 70GB RAID, so 1GB free is about 1.4% free, which makes for bad performance no matter what filesystem you have. In general, ext2 will have this 1% free space spread evenly across all of the disk, so while 1GB is still a lot of space, it is still a nearly full filesystem. Cheers, Andreas -- Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto, \ would they cancel out, leaving him still hungry?" http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert