From owner-freebsd-questions Sat May 5 19:55:43 2001 Delivered-To: freebsd-questions@freebsd.org Received: from schmoo.tclme.org (schmoo.tclme.org [208.24.53.96]) by hub.freebsd.org (Postfix) with SMTP id 6A05A37B422 for ; Sat, 5 May 2001 19:55:40 -0700 (PDT) (envelope-from rgreene@tclme.org) Received: (qmail 69568 invoked by uid 1014); 6 May 2001 02:54:25 -0000 Received: from dialup7.austintx.com (HELO tclme.org) (rgreene@208.24.53.9) by mail.tclme.org with SMTP; 6 May 2001 02:54:25 -0000 Message-ID: <3AF4BF5A.A03D7278@tclme.org> Date: Sat, 05 May 2001 22:04:58 -0500 From: Bob Greene Organization: tclme.org X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.2-2 i686) X-Accept-Language: en MIME-Version: 1.0 To: Greg Lehey Cc: "Andrew C. Hornback" , Steve Blanzy , FreeBSD Questions Subject: Re: Raid References: <000a01c0d57f$2158bb40$0400a8c0@192.168.0.1> <000701c0d581$3dd2da60$0e00000a@tomcat> <20010506101618.B39554@wantadilla.lemis.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Greg Lehey wrote: > > No, RAID-1 gives you the best performance of any RAID setup. The > reason why you need at least 3 disks for RAID-5 is because it is > slower, and though it would theoretically work with only two disks, > it has no advantages over RAID-1 in this configuration. > Huh? This paragraph makes no sense. RAID 0 = striped set RAID 1 = mirrored set RAID 5 = striped set with parity RAID 1 gives maximum redundancy, at the cost of two writes. The third disk in RAID 5 is not a consequence of performance, it's a requirement for redundancy. RAID 5 with only 2 disks is a failure condition of a 3 disk array. At that point it's effectively just a striped set. -- Bob Greene rgreene@TclMe.org Pull my finger for my public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message