From oracle-l-bounce@freelists.org Thu Sep 9 20:56:31 2004 Return-Path: Received: from air189.startdedicated.com (root@localhost) by orafaq.com (8.11.6/8.11.6) with ESMTP id i8A1t6a26155 for ; Thu, 9 Sep 2004 20:55:51 -0500 X-ClientAddr: 206.53.239.180 Received: from turing.freelists.org (freelists-180.iquest.net [206.53.239.180]) by air189.startdedicated.com (8.11.6/8.11.6) with ESMTP id i8A1sgI26135 for ; Thu, 9 Sep 2004 20:54:58 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 5674B72C5F8; Thu, 9 Sep 2004 21:00:25 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 22704-66; Thu, 9 Sep 2004 21:00:25 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 9BF3A72C628; Thu, 9 Sep 2004 21:00:24 -0500 (EST) From: "Cary Millsap" To: Subject: RE: Re[2]: Raid5 Vs Raid0+1 -- Raw Vs Solaris 9 Concurrent Direct IO UFS Date: Thu, 9 Sep 2004 20:57:55 -0500 Message-ID: <001f01c496d9$99d3ca00$6701a8c0@CVMLAP02> MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-archive-position: 9353 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: cary.millsap@hotsos.com Precedence: normal Reply-To: cary.millsap@hotsos.com X-list: oracle-l X-Virus-Scanned: by amavisd-new at freelists.org RAID 1+0 does so have parity. The formula is parity_bit = data_bit :) In this sense, RAID 1+0 is simply a special case of RAID 5. RAID 1+0 /is/ RAID 5 with G=2. Cary Millsap Hotsos Enterprises, Ltd. http://www.hotsos.com * Nullius in verba * Upcoming events: - Performance Diagnosis 101: 9/14 San Francisco, 10/5 Charlotte, 10/26 Toronto - SQL Optimization 101: 9/20 Hartford, 10/18 New Orleans - Hotsos Symposium 2005: March 6-10 Dallas - Visit www.hotsos.com for schedule details... -----Original Message----- From: oracle-l-bounce@freelists.org [mailto:oracle-l-bounce@freelists.org] On Behalf Of Jared.Still@radisys.com Sent: Thursday, September 09, 2004 4:37 PM To: edgar.chupit@rs.lv Cc: Oracle-L@freelists.org; oracle-l-bounce@freelists.org Subject: Re: Re[2]: Raid5 Vs Raid0+1 -- Raw Vs Solaris 9 Concurrent Direct IO UFS > Unless I'm missing something than according to raid specs it doesn't > mater how many disks are in raid5 array, you just need one additional > disk for checksums, so in case of 6 spindle array you can create raid5 > that will operate according to your schema (it actually will be two > raid5 arrays) or you can create one raid5 array that will use 5 disks > for data and one disk for checksums. > > Please, correct me if I'm wrong. > It sounds to me like you are describing a RAID volume with dedicated parity. If so, that is RAID 3. RAID 5 has distributed parity. RAID 1+0 has no parity. ;) Jared -- To unsubscribe - mailto:oracle-l-request@freelists.org&subject=unsubscribe To search the archives - http://www.freelists.org/archives/oracle-l/ -- To unsubscribe - mailto:oracle-l-request@freelists.org&subject=unsubscribe To search the archives - http://www.freelists.org/archives/oracle-l/