From owner-freebsd-questions Thu May 17 1:12:29 2001 Delivered-To: freebsd-questions@freebsd.org Received: from zork.punq.net (punq.net [207.154.84.94]) by hub.freebsd.org (Postfix) with SMTP id E6F2A37B423 for ; Thu, 17 May 2001 01:12:26 -0700 (PDT) (envelope-from marcus@blazingdot.com) Received: (qmail 4523 invoked by uid 1000); 17 May 2001 08:12:26 -0000 Date: Thu, 17 May 2001 01:12:26 -0700 From: Marcus Reid To: Greg Lehey Cc: Gabriel Ambuehl , Jonathan Fortin , questions@freebsd.org Subject: Re: Raid (BEST PERFORMANCE) Message-ID: <20010517011226.A4473@blazingdot.com> References: <007501c0d718$61d4d920$020a10ac@node00> <721044900156.20010508182226@buz.ch> <20010516220747.A3755@blazingdot.com> <20010517165026.V12294@wantadilla.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010517165026.V12294@wantadilla.lemis.com>; from grog@lemis.com on Thu, May 17, 2001 at 04:50:26PM +0930 Coffee-Level: high Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thu, May 17, 2001 at 04:50:26PM +0930, Greg Lehey wrote: > On Wednesday, 16 May 2001 at 22:07:48 -0700, Marcus Reid wrote: > > On Tue, May 08, 2001 at 06:22:26PM +0200, Gabriel Ambuehl wrote: > >> > >> Hello Jonathan, > >> Monday, May 07, 2001, 7:08:48 PM, you wrote: > >>> Best Performance Raid is a raid 0+1 setup. > >>> For example, you got 4 20gb harddrives. > >>> You create 2 strips of 2hds eachs, and you mirror them. > >>> It will have redundancy and the speed will be as fast as a normal > >> disk. It's > >>> basically a Raid-1 setup with 2 hard drives per strip instead of one > >> to > >>> counter write performance hits. > >> Some vendors like to call this RAID 10 (hmm. 1+0=10? only if those are > >> strings...). > > > > If I'm not mistaken, there's a difference between 0+1 and 10: one is > > striped and then mirrored, the other is mirrored and then striped. It's > > supposed to have some bearing on performance, 0+1 being the faster one. > > I've heard people make this kind of claim. I can't understand what > the difference is supposed to be. Can you justify it? It's something that I read on the qmail list; people were talking about the best RAID scheme to use for a very high-volume mail server. I don't have anything to offer from personal experience. I'm assembling a new mail machine very soon and have to select which level of RAID to use, so I'd be interested to hear if there's any truth behind it. Marcus To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message