From owner-freebsd-questions Sat May 5 17:46:25 2001 Delivered-To: freebsd-questions@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id 33CA837B423 for ; Sat, 5 May 2001 17:46:21 -0700 (PDT) (envelope-from grog@lemis.com) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id E2F026ACBD; Sun, 6 May 2001 10:16:18 +0930 (CST) Date: Sun, 6 May 2001 10:16:18 +0930 From: Greg Lehey To: "Andrew C. Hornback" Cc: Steve Blanzy , FreeBSD Questions Subject: Re: Raid Message-ID: <20010506101618.B39554@wantadilla.lemis.com> References: <000a01c0d57f$2158bb40$0400a8c0@192.168.0.1> <000701c0d581$3dd2da60$0e00000a@tomcat> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <000701c0d581$3dd2da60$0e00000a@tomcat>; from hornback@wireco.net on Sat, May 05, 2001 at 12:34:23PM -0400 Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG [Format recovered--see http://www.lemis.com/email/email-format.html] Paragraphs have no line breaks. On Saturday, May 05, 2001 12:19 PM, Steve Blanzy wrote: > On Saturday, 5 May 2001 at 12:34:23 -0400, Andrew C. Hornback wrote: >> What RAID if any does free BSD support in a dual SCSI hard drive configuration? > a> (ACK! Please don't send HTML-ized e-mail to the list!) In fact, his message was multipart-alternative. Your MUA shouldn't have any difficulty with that. But please adjust it to make text lines of < 80 characters. >> And about your question... from personal experience, the only >> two forms of RAID that you can use with two drives, no matter which >> OS, are RAID 0 and RAID 1. >> >> RAID 0 is pure striping across both drives, which offers no >> redundancy but may offer better throughput. In fact, as the number suggests, this isn't RAID (Redundant Array of (Inexpensive) Disks) at all. >> RAID 1 is pure mirroring, which offers the best redundancy but may >> cause a severe penalty on disk subsystem performance. 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. You can set up RAID either with a specialized controller ("hardware RAID") or with Vinum (see vinum(4) and vinum(8), also http://www.vinum-vm.org/). Greg -- When replying to this message, please take care not to mutilate the original text. For more information, see http://www.lemis.com/email.html Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message