From owner-freebsd-questions Sun Mar 9 17:15:41 2003 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 5159F37B401 for ; Sun, 9 Mar 2003 17:15:40 -0800 (PST) Received: from out004.verizon.net (out004pub.verizon.net [206.46.170.142]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7160843F75 for ; Sun, 9 Mar 2003 17:15:39 -0800 (PST) (envelope-from cswiger@mac.com) Received: from mac.com ([129.44.42.236]) by out004.verizon.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20030310011538.SPOK7930.out004.verizon.net@mac.com> for ; Sun, 9 Mar 2003 19:15:38 -0600 Message-ID: <3E6BE734.4040804@mac.com> Date: Sun, 09 Mar 2003 20:15:32 -0500 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3b) Gecko/20030210 X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd Questions Subject: Re: Difference between Vinum and atacontrol RAID? References: <20030309233502.GC1899@bubba.toscano.org> In-Reply-To: <20030309233502.GC1899@bubba.toscano.org> 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 out004.verizon.net from [129.44.42.236] at Sun, 9 Mar 2003 19:15:38 -0600 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Pete wrote: [ ... ] > I thought Vinum was FreeBSD's RAID system. If you wanted to do software > RAID with FreeBSD, you needed to use Vinum. Now I find this out. Does > that ATA subsystem have RAID support built in? (Since atacontrol just > seems to control the ATA devices...) If this is so, what's the use of > Vinum? When should I use one vs the other? How do Vinum and the ATA > subsystem's RAID relate? Vinum resembles a popular commercial RAID product called Veritas LVM; vinum does software-based RAID. The ATA RAID support via atacontrol apparently requires hardware RAID controllers like the Promise or Highpoint devices. Hardware based RAID is likely to be faster, particularly in the case of parity calculations for RAID-5. (Not that many IDE controllers can do RAID-5, but...) The RAID volumes created with vinum are accessible only under FreeBSD, whereas the ATA-based RAID solutions create a logical volume accessible via the normal BIOS interfaces, so the RAID device looks like a single, bigger physical disk drive. Thus you can use an ATA-based hardware RAID volume as a boot device, install multiple operating systems, etc. Generally, one cannot boot from a vinum based-device, unless you are only doing RAID-1 mirroring. I'm familar with something called "encapsulating the root partition" under Solaris and Veritas; it's not for the faint-of-heart. :-) -Chuck To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message