From owner-freebsd-geom@FreeBSD.ORG Fri Sep 16 10:42:21 2005 Return-Path: X-Original-To: freebsd-geom@freebsd.org Delivered-To: freebsd-geom@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 70A3416A41F for ; Fri, 16 Sep 2005 10:42:21 +0000 (GMT) (envelope-from sudakov@sibptus.tomsk.ru) Received: from relay2.tomsk.ru (relay2.tomsk.ru [212.73.124.8]) by mx1.FreeBSD.org (Postfix) with ESMTP id A057C43D46 for ; Fri, 16 Sep 2005 10:42:20 +0000 (GMT) (envelope-from sudakov@sibptus.tomsk.ru) X-Virus-Scanned: by Dr.Web (R) daemon for FreeBSD, version 4.32.1 (2004-08-30) at relay2.tomsk.ru X-Spam-Checker-Version: SpamAssassin 3.0.4 on relay2.tomsk.ru Received: from [172.16.138.125] (account sudakovva@sibptus.tomsk.ru HELO admin.sibptus.tomsk.ru) by relay2.tomsk.ru (CommuniGate Pro SMTP 4.3.2) with ESMTPSA id 1203329 for freebsd-geom@freebsd.org; Fri, 16 Sep 2005 17:42:17 +0700 Received: (from sudakov@localhost) by admin.sibptus.tomsk.ru (8.12.9p2/8.12.9/Submit) id j8GAgGpF033634 for freebsd-geom@freebsd.org; Fri, 16 Sep 2005 17:42:16 +0700 (OMSST) (envelope-from sudakov) Date: Fri, 16 Sep 2005 17:42:16 +0700 From: Victor Sudakov To: freebsd-geom@freebsd.org Message-ID: <20050916104216.GA33576@admin.sibptus.tomsk.ru> References: <20050916073012.GA31056@admin.sibptus.tomsk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050916073012.GA31056@admin.sibptus.tomsk.ru> User-Agent: Mutt/1.4.2.1i Organization: AO "Svyaztransneft", SibPTUS X-PGP-Key: http://vas.tomsk.ru/vas.asc Subject: Re: Create a mirror on disk with valid data X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Sep 2005 10:42:21 -0000 Victor Sudakov wrote: > > How could it then be possible to create a mirror from a disk with > existing data, like the man page suggests? The gmirror metadata could > then be overwritten with user data or vice versa. Perhaps someone would like to comment on this, which I think proves my point: testbsd5# dd if=/dev/zero of=/dev/ad2 count=500 500+0 records in 500+0 records out 256000 bytes transferred in 1.243238 secs (205914 bytes/sec) testbsd5# fdisk -BI ad2 ******* Working on device /dev/ad2 ******* fdisk: invalid fdisk partition table found testbsd5# fdisk -BI ad2 ******* Working on device /dev/ad2 ******* testbsd5# disklabel -w /dev/ad2s1 auto testbsd5# newfs ad2s1a /dev/ad2s1a: 1023.7MB (2096560 sectors) block size 16384, fragment size 2048 using 6 cylinder groups of 183.77MB, 11761 blks, 23552 inodes. super-block backups (for fsck -b #) at: 160, 376512, 752864, 1129216, 1505568, 1881920 testbsd5# testbsd5# gmirror label gm1 ad2 testbsd5# newfs /dev/mirror/gm1s1a newfs: wtfs: 512 bytes at sector 2096560: Unknown error: 0 testbsd5# testbsd5# disklabel /dev/mirror/gm1s1 # /dev/mirror/gm1s1: 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 2096561 16 4.2BSD 2048 16384 28552 c: 2096577 0 unused 0 0 # "raw" part, don't edit testbsd5# -- Victor Sudakov, VAS4-RIPE, VAS47-RIPN