From owner-freebsd-stable@FreeBSD.ORG Sun Mar 30 07:27:09 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 41EA037B425 for ; Sun, 30 Mar 2003 07:27:09 -0800 (PST) Received: from out003.verizon.net (out003pub.verizon.net [206.46.170.103]) by mx1.FreeBSD.org (Postfix) with ESMTP id 19DCB43FA3 for ; Sun, 30 Mar 2003 07:27:08 -0800 (PST) (envelope-from cswiger@mac.com) Received: from mac.com ([129.44.43.88]) by out003.verizon.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20030330152707.VJMV15663.out003.verizon.net@mac.com>; Sun, 30 Mar 2003 09:27:07 -0600 Message-ID: <3E870CC7.5000204@mac.com> Date: Sun, 30 Mar 2003 10:27:03 -0500 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3) Gecko/20030312 X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-stable@freebsd.org References: <20030330125138.K23911@leelou.in.tern> In-Reply-To: <20030330125138.K23911@leelou.in.tern> X-Enigmail-Version: 0.73.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Authentication-Info: Submitted using SMTP AUTH at out003.verizon.net from [129.44.43.88] at Sun, 30 Mar 2003 09:27:07 -0600 cc: Lukas Ertl 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 15:27:12 -0000 Lukas Ertl wrote: [ ... ] > I created several RAID 0 and RAID 5 volumes with different stripe sizes > and let bonnie++ run over the filesystems. I was quite disappointed about > the RAID 5 performance, and even the RAID 0 performance wasn't too good > (a plain single disk filesystem was almost as fast as or even faster than > a RAID 0 stripe, and I wouldn't expect that). > > RAID 5 performance was really a mess, some of the test took more than > 30min. to complete. There are three goals or priorities to choose from when configuring RAID: performance, reliability, and cost. What are yours? 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. Um, that is a dual-channel card, and you're splitting drives onto both channels, right? Anyway, if I had your hardware and no specs as to what to do, I'd probably configure 2 disks as a RAID-1 mirror for an OS boot volume; configure 4 disks as RAID-10; and use the 7th disk as a staging area, hot spare, etc. -- -Chuck