From owner-freebsd-performance@FreeBSD.ORG Thu Jun 30 00:21:42 2005 Return-Path: X-Original-To: performance@freebsd.org Delivered-To: freebsd-performance@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BD1AD16A41C for ; Thu, 30 Jun 2005 00:21:42 +0000 (GMT) (envelope-from bde@zeta.org.au) Received: from mailout1.pacific.net.au (mailout1.pacific.net.au [61.8.0.84]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5919443D53 for ; Thu, 30 Jun 2005 00:21:42 +0000 (GMT) (envelope-from bde@zeta.org.au) Received: from mailproxy1.pacific.net.au (mailproxy1.pacific.net.au [61.8.0.86]) by mailout1.pacific.net.au (8.13.4/8.13.4/Debian-3) with ESMTP id j5U0LfmC020685; Thu, 30 Jun 2005 10:21:41 +1000 Received: from katana.zip.com.au (katana.zip.com.au [61.8.7.246]) by mailproxy1.pacific.net.au (8.13.4/8.13.4/Debian-3) with ESMTP id j5U0LcbJ019626; Thu, 30 Jun 2005 10:21:39 +1000 Date: Thu, 30 Jun 2005 10:21:38 +1000 (EST) From: Bruce Evans X-X-Sender: bde@delplex.bde.org To: Jeremie Le Hen In-Reply-To: <20050629094533.GA49933@obiwan.tataz.chchile.org> Message-ID: <20050630100814.O45160@delplex.bde.org> References: <20050623145041.GC64879@bibipentium.lonres.com> <42BD64F1.4080001@roq.com> <20050627134146.GA626@bibipentium.lonres.com> <42C1FA31.3050806@roq.com> <20050629094533.GA49933@obiwan.tataz.chchile.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: Michael Vince , Steve Roome , performance@freebsd.org Subject: Re: FreeBSD MySQL still WAY slower than Linux X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Jun 2005 00:21:42 -0000 On Wed, 29 Jun 2005, Jeremie Le Hen wrote: > Could you try mounting the filesystem where the database lives with > the noatime option, and re-run your tests ? IIRC from previous threads > on this subject, Linux doesn't really honor this while FreeBSD does, > which pulls down the performances. I think you mean the async option. Neither would make much differerce. atimes are cached in ffs, so mounting with noatime only makes much difference if lots of different files are read, which is exactly what doesn't happen when data is in a database instead of in separate files. Mounting with async can make a large difference, but normally makes no difference with ffs, since ffs is normally configured with soft updates and the async option is silently ignored in this configuration. You could try mounting with the sync option for all OSes. This should make them all very slow, but the results might be interesting since it is the only sync-related mount option that gives similar behaviour at the fs level. It might also show if the problem is related to syncing. Bruce