From owner-freebsd-performance@FreeBSD.ORG Tue Oct 19 21:04:58 2004 Return-Path: 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 2CCF616A4CE for ; Tue, 19 Oct 2004 21:04:58 +0000 (GMT) Received: from mail.geeks.org (jacobs.Geeks.ORG [204.153.247.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id D4B3843D1F for ; Tue, 19 Oct 2004 21:04:57 +0000 (GMT) (envelope-from drechsau@Geeks.ORG) Received: by mail.geeks.org (Postfix, from userid 400) id 65C6F20B60; Tue, 19 Oct 2004 16:04:57 -0500 (CDT) Date: Tue, 19 Oct 2004 16:04:57 -0500 From: Mike Horwath To: Kristofer Pettijohn Message-ID: <20041019210457.GH39270@octanews.net> References: <20041019193501.GC78974@cybernetik.net> <41756EBF.3010008@jonny.eng.br> <20041019210241.GB80878@cybernetik.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041019210241.GB80878@cybernetik.net> X-PGP-Fingerprint: D8 24 CC E6 47 5F E4 60 BF B7 6E FA BF C7 6E C5 X-GPG-Fingerprint: 6A89 E78A B8B1 69D9 8CDB E966 4A5A C3F9 A1B0 C381 User-Agent: Mutt/1.5.6i cc: freebsd-performance@freebsd.org cc: Jo?o Carlos Mendes Lu?s Subject: Re: Disk I/O Performance X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Oct 2004 21:04:58 -0000 On Tue, Oct 19, 2004 at 04:02:41PM -0500, Kristofer Pettijohn wrote: > On Tue, Oct 19, 2004 at 04:45:03PM -0300, Jo?o Carlos Mendes Lu?s wrote: > > I'd say that you have to check which CCD chunk size is best for > > your needs. The manual for vinum recommends avoiding chunk sized to a > > power of two, which is probably the first big mistake of everybody. > > I've tried a wide range of chunk sizes, from 128kB to 64MB.. also have > been avoiding powers of 2. The old idea from someone long ago was to set the stripe size the size of the cylinder block. I found 8MB to be pretty decent, though not perfect. > > Try mounting with option noatime, if you haven't already. And use > > the largest block size possible when formatting. Last time I read about > > there was a limit of 16384, but I would expect better performance for > > large file with 64k blocks (and 8k frags). > > The largest block size is 64k, and I have done that as well. Use this for tunefs - it made a little bit of a difference: tunefs -m 8 -o time /dev/something and make sure you set up the dspool.ctl file correctly because of the change. -- Mike Horwath, reachable via drechsau@Geeks.ORG