From owner-freebsd-questions Sat Jul 14 3:13:25 2001 Delivered-To: freebsd-questions@freebsd.org Received: from drex.staff.izr.com (drex.staff.izr.com [195.26.38.16]) by hub.freebsd.org (Postfix) with ESMTP id 41F3237B401; Sat, 14 Jul 2001 03:13:22 -0700 (PDT) (envelope-from mark@drex.staff.izr.com) Received: by drex.staff.izr.com (Postfix, from userid 1001) id 4723E3379E; Sat, 14 Jul 2001 11:13:41 +0100 (BST) Date: Sat, 14 Jul 2001 11:13:41 +0100 From: Mark Drayton To: Greg Lehey Cc: freebsd-questions@freebsd.org Subject: Re: Vinum mirrored/striped confusion Message-ID: <20010714111341.B63502@drex.staff.izr.com> Mail-Followup-To: Greg Lehey , freebsd-questions@freebsd.org References: <20010714004038.A58799@drex.staff.izr.com> <20010714092821.F99931@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: <20010714092821.F99931@wantadilla.lemis.com>; from grog@FreeBSD.org on Sat, Jul 14, 2001 at 09:28:21AM +0930 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Greg Lehey (grog@FreeBSD.org) wrote: > On Saturday, 14 July 2001 at 0:40:39 +0100, Mark Drayton wrote: > > > > I don't quite understand why mirroring two plexes containing the > > same subdisks is beneficial. What happens if, say, disk 1 fails? > > If you mean d1, then you'll lose the first 512 MB of plex 0 and the > last 512 MB of plex 1. These parts of the volume will no longer be > mirrored. Ah, I see now. > > I imagine both plexes will be faulty and the volume will be down > > This is incorrect. The volume will remain up. Excellent! I assumed a volume requires at least one 'up' plex to be up. Obviously this isn't the case. > > Aside from this possible difference, is one of these two setups > > going to perform better (for a mail server) than the other? > > Well, the second config only has half the storage :-) But if you made > those 1 GB subdisks, the performance should be comparable. Okay. Which of these configurations do you recommend? As far as I know, both configurations perform equally well, and a disk failure in either case will result in half the volume not being mirrored but with the volume remaining up. Is there any other pros/cons I should consider? Thanks very much, -- Mark Drayton izR Company Ltd To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message