From owner-freebsd-stable@FreeBSD.ORG Sun Mar 30 15:15:14 2003 Return-Path: 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 E045037B401 for ; Sun, 30 Mar 2003 15:15:14 -0800 (PST) Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by mx1.FreeBSD.org (Postfix) with ESMTP id 542CF43FA3 for ; Sun, 30 Mar 2003 15:15:13 -0800 (PST) (envelope-from grog@lemis.com) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id 5DD1251A6F; Mon, 31 Mar 2003 08:45:11 +0930 (CST) Date: Mon, 31 Mar 2003 08:45:11 +0930 From: Greg 'groggy' Lehey To: Lukas Ertl Message-ID: <20030330231511.GF1861@wantadilla.lemis.com> References: <20030330125138.K23911@leelou.in.tern> <3E870CC7.5000204@mac.com> <20030330175605.E23911@leelou.in.tern> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="rWhLK7VZz0iBluhq" Content-Disposition: inline In-Reply-To: <20030330175605.E23911@leelou.in.tern> User-Agent: Mutt/1.4i Organization: The FreeBSD Project Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.FreeBSD.org/ X-PGP-Fingerprint: 9A1B 8202 BCCE B846 F92F 09AC 22E6 F290 507A 4223 cc: freebsd-stable@freebsd.org Subject: Re: vinum performance X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 Mar 2003 23:15:16 -0000 --rWhLK7VZz0iBluhq Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sunday, 30 March 2003 at 18:00:01 +0200, Lukas Ertl wrote: > On Sun, 30 Mar 2003, Chuck Swiger wrote: > >> Lukas Ertl wrote: >> [ ... ] >> Also, what tasks you intend to use the RAID filesystem for are critical >> to consider, even if the answer is simply "undifferentiated >> general-purpose storage". In particular, RAID-5 write performance is >> going to be slow, even with RAID hardware support which offloads the >> parity calculations from the system CPU(s). RAID-5 is best suited for >> read-mostly or read-only volumes, where you value cost more than >> performance. > > Ok. But I still don't understand why RAID 5 write performance is > _so_ bad. That's certainly something to investigate. > The CPU is not the bottle neck, it's rather bored. And I don't > understand why RAID 0 doesn't give a big boost at all. What can it do? You're only writing one file at a time. > Is the ahc driver known to be slow? This is definitely not a driver performance issue. Greg -- See complete headers for address and phone numbers --rWhLK7VZz0iBluhq Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.0 (FreeBSD) iD8DBQE+h3p/IubykFB6QiMRAlsGAKCfKN+iary86RtrBLQ9vnH4nhqxlwCaAsuv zOGzm9ELJCWnh+DliUmiqJw= =QKX1 -----END PGP SIGNATURE----- --rWhLK7VZz0iBluhq--