From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1Fy56X-0000Jk-Ht for garchives@archives.gentoo.org; Wed, 05 Jul 2006 10:59:37 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.7/8.13.6) with SMTP id k65AuJKY022667; Wed, 5 Jul 2006 10:56:19 GMT Received: from ilievnet.com ([84.21.204.200]) by robin.gentoo.org (8.13.7/8.13.6) with ESMTP id k65AhJGx029826 for ; Wed, 5 Jul 2006 10:43:19 GMT Received: (qmail 29685 invoked from network); 5 Jul 2006 13:43:18 +0300 Received: from unknown (HELO ?10.0.1.11?) (10.0.1.11) by 0 with SMTP; 5 Jul 2006 13:43:18 +0300 Message-ID: <44AB97C6.4040801@ilievnet.com> Date: Wed, 05 Jul 2006 13:43:18 +0300 From: Daniel User-Agent: Thunderbird 1.5.0.4 (X11/20060704) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] linux' IO performance sucks References: In-Reply-To: X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by robin.gentoo.org id k65AuJKq022667 X-Archives-Salt: 60532c8b-a49f-4227-95b1-d40fa2f32f37 X-Archives-Hash: e2da1c2933d1f76318af41d7d789f73e Sven K=F6hler wrote: > Hi, >=20 > sorry for the silly subject, but did you ever experience the following?= : >=20 > i have a fileserver, i copy a file to it - let's say 600MB. >=20 > So about every 200MB (i guess the linux box writes the data into the > cache in the RAM first) linux writes the harddisk. But during that time > - during the time it writes that 200MB to disk, there is no chance for > any other IO. I'm playing an mp3 from the very same fileserver. It stop= s > playing, because the machine does answer the read-requests. >=20 > So what's going on here? >=20 > Why does Linux write so huge amounts of data to the disk? Why does Linu= x > not stop writing for a while to fullfil the read-requests? And so on ... >=20 > Any idea, on how to imrpove that? >=20 Perhaps a more often flush of buffers may help you in this situation. There are several parameters you can tweak to control your kernel behavior regarding this. You can put the following lines in your /etc/sysctl.conf file, replacing "i","j","k" and "l" with proper numbers. vm.dirty_expire_centisecs =3D i vm.dirty_writeback_centisecs =3D j vm.dirty_ratio =3D k vm.dirty_background_ratio =3D l The meaning of these parameters is descibed in the kernel documentation: /usr/src/linux/Documentation/filesystems/proc.txt /usr/src/linux/Documentation/sysctl/vm.txt You could also disable all write caching by issuing the command: hdparm -W0 /dev/ Hope This Helps --- Best regards Daniel --=20 gentoo-user@gentoo.org mailing list