Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751920AbWJWL3b (ORCPT ); Mon, 23 Oct 2006 07:29:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751922AbWJWL3b (ORCPT ); Mon, 23 Oct 2006 07:29:31 -0400 Received: from rgminet01.oracle.com ([148.87.113.118]:53704 "EHLO rgminet01.oracle.com") by vger.kernel.org with ESMTP id S1751920AbWJWL3a (ORCPT ); Mon, 23 Oct 2006 07:29:30 -0400 Date: Mon, 23 Oct 2006 07:29:20 -0400 From: Chris Mason To: Brice Figureau Cc: linux-kernel@vger.kernel.org Subject: Re: Sluggish system while copying large files. Message-ID: <20061023112920.GA5560@think.oraclecorp.com> References: <1160747774.7929.53.camel@localhost.localdomain> <20061018150901.GC16570@think.oraclecorp.com> <1161596405.473.29.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1161596405.473.29.camel@localhost.localdomain> User-Agent: Mutt/1.5.12-2006-07-14 X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1543 Lines: 39 On Mon, Oct 23, 2006 at 11:40:05AM +0200, Brice Figureau wrote: > > I'll try the data=writeback mount option. Is it possible to remount the > partition and change the journal option on a running system? Not with ext3, sorry. > > > Since mysql is probably triggering tons of fsyncs or O_SYNC writes, > > you may want to increase the size of the ext3 log. > > Mysql is using O_DIRECT for its datafile. I don't know how it relates to > the sync things, but I guess that to be truly ACID, it has to fsync the > files on each transactions. > How can I increase the ext3 log ? > Any idea of the size I should use (and what is the default) ? Even when using O_DIRECT, if the file is extended an FS commit is triggered to record the extension. > > > If mysql is constantly appending to the files holding your tables, the > > synchronous writes are more expensive and log intensive. Check your > > setup to see if you can manually extend any of those files to avoid > > constantly growing table files. > > The use of a battery-backed RAID cache should mitigate the sync writes, > and since our mysql load is quite low, the machine shouldn't definitely > freeze for seconds while copying files. Ok, I would start with only doing data=writeback. That is probably a big part of the problem. -chris - 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/