From owner-freebsd-questions Fri Jul 13 16:40:28 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 9B15A37B401 for ; Fri, 13 Jul 2001 16:40:24 -0700 (PDT) (envelope-from mark@drex.staff.izr.com) Received: by drex.staff.izr.com (Postfix, from userid 1001) id 1D0253379E; Sat, 14 Jul 2001 00:40:39 +0100 (BST) Date: Sat, 14 Jul 2001 00:40:39 +0100 From: Mark Drayton To: freebsd-questions@freebsd.org Subject: Vinum mirrored/striped confusion Message-ID: <20010714004038.A58799@drex.staff.izr.com> Mail-Followup-To: freebsd-questions@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i 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 Hi I'm trying to set up a machine with a striped and mirrored set for use with postfix and cyrus. From vinum(8): You may want to have the best of both worlds and have both resilience and performance. This is sometimes called RAID-10 (a combination of RAID-1 and RAID-0), though again this name is misleading. With vinum you can do this with the following configuration file: drive d1 device /dev/da2e drive d2 device /dev/da3e drive d3 device /dev/da4e drive d4 device /dev/da5e volume raid setupstate plex org striped 512k sd length 512m drive d1 sd length 512m drive d2 sd length 512m drive d3 sd length 512m drive d4 plex org striped 512k sd length 512m drive d4 sd length 512m drive d3 sd length 512m drive d2 sd length 512m drive d1 I don't quite understand why mirroring two plexes containing the same subdisks is beneficial. What happens if, say, disk 1 fails? I imagine both plexes will be faulty and the volume will be down which (to me) almost defies the point of mirroring. drive d1 device /dev/da2e drive d2 device /dev/da3e drive d3 device /dev/da4e drive d4 device /dev/da5e volume raid setupstate plex org striped 512k sd length 512m drive d1 sd length 512m drive d2 plex org striped 512k sd length 512m drive d3 sd length 512m drive d4 If disk 1 failed with this setup, will the volume still be up with one of its plexes in the faulty state? Aside from this possible difference, is one of these two setups going to perform better (for a mail server) than the other? Please point me in the right direction if I need to RTFM! Cheers, -- Mark Drayton izR Company Ltd To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message