From owner-freebsd-questions@FreeBSD.ORG Thu Aug 5 07:25:23 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AE78716A4CE for ; Thu, 5 Aug 2004 07:25:23 +0000 (GMT) Received: from pcwin002.win.tue.nl (pcwin002.win.tue.nl [131.155.71.72]) by mx1.FreeBSD.org (Postfix) with ESMTP id 24F3643D54 for ; Thu, 5 Aug 2004 07:25:23 +0000 (GMT) (envelope-from stijn@pcwin002.win.tue.nl) Received: from pcwin002.win.tue.nl (orb_rules@localhost [127.0.0.1]) by pcwin002.win.tue.nl (8.12.11/8.12.11) with ESMTP id i757PMT7053367; Thu, 5 Aug 2004 09:25:22 +0200 (CEST) (envelope-from stijn@pcwin002.win.tue.nl) Received: (from stijn@localhost) by pcwin002.win.tue.nl (8.12.11/8.12.11/Submit) id i757PMge053366; Thu, 5 Aug 2004 09:25:22 +0200 (CEST) (envelope-from stijn) Date: Thu, 5 Aug 2004 09:25:22 +0200 From: Stijn Hoop To: "H. Sandring" Message-ID: <20040805072521.GH43462@pcwin002.win.tue.nl> Mail-Followup-To: Stijn Hoop , "H. Sandring" , freebsd-questions@freebsd.org References: <003601c47aba$2dd9ca10$0501a8c0@kojo> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="SnV5plBeK2Ge1I9g" Content-Disposition: inline In-Reply-To: <003601c47aba$2dd9ca10$0501a8c0@kojo> User-Agent: Mutt/1.4.2.1i X-Bright-Idea: Let's abolish HTML mail! cc: freebsd-questions@freebsd.org Subject: Re: RAID 5 stripe size X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 05 Aug 2004 07:25:23 -0000 --SnV5plBeK2Ge1I9g Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Thu, Aug 05, 2004 at 03:02:25PM +0800, H. Sandring wrote: > Is there an intelligent way of choosing the stripe size of a RAID 5 > array? =46rom man vinum: "For optimum performance, stripes should be at least 128 kB in size: anythi= ng smaller will result in a significant increase in I/O activ- ity due to mapp= ing of individual requests over multiple disks. The performance improvement due to the increased number of concurrent transfers caused by this mapping will not make up for the performance drop due to the increase in latency. A good guideline for stripe size is between 256 kB and 512 kB. Avoid powers of 2, however: they tend to cause all superblocks to be placed on the first subdi= sk." I expect this to be true for non-vinum RAID-5 volumes as well. HTH, --Stijn --=20 The most reliable proof that there are extraterrestrial intelligent lifeforms out there is that nobody actually tries to get in contact with us. -- Dirk Mueller --SnV5plBeK2Ge1I9g Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFBEeDhY3r/tLQmfWcRAonLAJ0R814R3HFIy7blSw6puUSEO4OEQwCdFLMC l5z28RNS0aIC6DecCpRf2DA= =s4GF -----END PGP SIGNATURE----- --SnV5plBeK2Ge1I9g--