From owner-freebsd-questions@FreeBSD.ORG Wed Mar 21 14:32:32 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id C685316A400 for ; Wed, 21 Mar 2007 14:32:32 +0000 (UTC) (envelope-from lists@jnielsen.net) Received: from ns1.jnielsen.net (ns1.jnielsen.net [69.55.238.237]) by mx1.freebsd.org (Postfix) with ESMTP id AA02013C4DA for ; Wed, 21 Mar 2007 14:32:32 +0000 (UTC) (envelope-from lists@jnielsen.net) Received: from localhost (jn@ns1 [69.55.238.237]) (authenticated bits=0) by ns1.jnielsen.net (8.12.9p2/8.12.9) with ESMTP id l2LEWPXl046485; Wed, 21 Mar 2007 10:32:28 -0400 (EDT) (envelope-from lists@jnielsen.net) From: John Nielsen To: freebsd-questions@freebsd.org Date: Wed, 21 Mar 2007 10:33:03 -0400 User-Agent: KMail/1.9.6 References: <4600D8D9.3010401@charter.net> In-Reply-To: <4600D8D9.3010401@charter.net> X-Face: #X5#Y*q>F:]zT!DegL3z5Xo'^MN[$8k\[4^3rN~wm=s=Uw(sW}R?3b^*f1Wu*.<=?utf-8?q?of=5F4NrS=0A=09P*M/9CpxDo!D6?=)IY1w<9B1jB; tBQf[RU-R<,I)e"$q7N7 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200703211033.03337.lists@jnielsen.net> X-Virus-Scanned: ClamAV version 0.88.4, clamav-milter version 0.88.4 on ns1.jnielsen.net X-Virus-Status: Clean Cc: Gabriel Rossetti Subject: Re: Best software raid 5 software? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Mar 2007 14:32:32 -0000 On Wednesday 21 March 2007 03:03:53 am Gabriel Rossetti wrote: > I am about to switch to software raid 5 for my personal server. I know > hardware raid 5 is better, but being a student I'd rather not invest in > a raid adapter now, plus my cpu is being used at about 0.0% 24/24 7/7, > so it needs some exercise :-) > > I've heard of several software-based raid-5 projects, mainly of Vinum, > has anybody tested it or any other ones? > Which would you suggest? As far as I know, gvinum is the only software package in FreeBSD that can do RAID 5. The initial learning curve is a bit steep, but it should work fine once you get it configured. I would also suggest that you look at graid3 which, not surprisingly, supports RAID 3. As you may or may not know, RAID 3 is very similar to RAID 5. You get S*(N-1) usable space, where S is your disk size and N is the number of disks. You need at least three disks but can use more. Both allow you to lose any single disk and not lose any data. The difference is that RAID 5 stripes the redundant parity data across all of the disks and RAID 3 uses a single disk for all parity writes. As a result, RAID 5 potentially offers somewhat better read performance if disk I/O is the bottleneck (and assuming each disk has its own controller/I/O path). In the case of software raid and commodity (non-server) hardware, the difference should be nominal. Other software RAID options include gmirror (recommended for RAID1), gstripe (recommended for RAID0, can be combined w/ gmirror), ataraid (supports RAID0, RAID1, JBOD, and combinations on ata controllers only), and ccd (supports RAID0, RAID1, and JBOD; largely deprecated by gmirror and gstripe). JN