From owner-freebsd-stable@FreeBSD.ORG Tue Oct 24 09:17:26 2006 Return-Path: X-Original-To: stable@freebsd.org Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 79D3316A403 for ; Tue, 24 Oct 2006 09:17:26 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail09.syd.optusnet.com.au (mail09.syd.optusnet.com.au [211.29.132.190]) by mx1.FreeBSD.org (Postfix) with ESMTP id A135A43D46 for ; Tue, 24 Oct 2006 09:17:25 +0000 (GMT) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (c58-107-94-118.belrs4.nsw.optusnet.com.au [58.107.94.118]) by mail09.syd.optusnet.com.au (8.12.11/8.12.11) with ESMTP id k9O9HJcG029590 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Tue, 24 Oct 2006 19:17:21 +1000 Received: from turion.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by turion.vk2pj.dyndns.org (8.13.8/8.13.8) with ESMTP id k9O8kVG1001268; Tue, 24 Oct 2006 18:46:31 +1000 (EST) (envelope-from peter@turion.vk2pj.dyndns.org) Received: (from peter@localhost) by turion.vk2pj.dyndns.org (8.13.8/8.13.8/Submit) id k9O8kV3V001267; Tue, 24 Oct 2006 18:46:31 +1000 (EST) (envelope-from peter) Date: Tue, 24 Oct 2006 18:46:30 +1000 From: Peter Jeremy To: Ronald Klop , Mike Jakubik , stable@freebsd.org Message-ID: <20061024084630.GB916@turion.vk2pj.dyndns.org> References: <453D49D2.1010705@rogers.com> <3861E2E8-4232-4C46-8D0A-1B6079BCA07D@mac.com> <453D53ED.5050403@rogers.com> <5B0599EE-17BE-44E1-8CEC-587FFF1D79C4@mac.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="eJnRUKwClWJh1Khz" Content-Disposition: inline In-Reply-To: X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.13 (2006-08-11) Cc: Subject: Re: Running large DB's on FreeBSD X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Oct 2006 09:17:26 -0000 --eJnRUKwClWJh1Khz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, 2006-Oct-24 02:21:06 +0200, Ronald Klop wrote: >>On Oct 23, 2006, at 4:44 PM, Mike Jakubik wrote: >>>advanced features, but if they are not used, then what is the =20 >>>advantage? (I really like the InnooDB storage in MySQL) One nice thing about MySQL is the plethora of backends - you can pick the backend to suit the type of data and access methods. >Example: writing 1 bit on 1 disk needs to read some info from all disks to= =20 >recalculate the parity. So this doesn't scale very well. Any sane RAID-5 implementation will regenerate the parity by new_parity =3D old_parity XOR old_data XOR new_data Though this still turns a single write into 2 reads and 2 writes. Basically: Don't use RAID-5. --=20 Peter Jeremy --eJnRUKwClWJh1Khz Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (FreeBSD) iD8DBQFFPdLm/opHv/APuIcRAgKmAJ9XpzSCUYKmWSUv2wlhixyhXxzpHgCbBTb9 FzYWpqS1EF0lzIBLKAxjdFg= =qr5B -----END PGP SIGNATURE----- --eJnRUKwClWJh1Khz--