From owner-freebsd-questions@FreeBSD.ORG Tue Jun 10 15:09:29 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A85DB106564A for ; Tue, 10 Jun 2008 15:09:29 +0000 (UTC) (envelope-from sonicy@otenet.gr) Received: from rosebud.otenet.gr (rosebud.otenet.gr [195.170.0.94]) by mx1.freebsd.org (Postfix) with ESMTP id 3A22C8FC17 for ; Tue, 10 Jun 2008 15:09:28 +0000 (UTC) (envelope-from sonicy@otenet.gr) Received: from atlantis.dyndns.org (athedsl-4367213.home.otenet.gr [79.130.19.93]) by rosebud.otenet.gr (8.13.8/8.13.8/Debian-3) with ESMTP id m5AF9PmT024199; Tue, 10 Jun 2008 18:09:26 +0300 Message-ID: <484E9925.2050507@otenet.gr> Date: Tue, 10 Jun 2008 18:09:25 +0300 From: Manolis Kiagias User-Agent: Thunderbird 2.0.0.14 (X11/20080607) MIME-Version: 1.0 To: Erik Trulsson References: <484EACEB.7169.43FE1258@iwrtech.iwr.ru.ac.za> <20080610145926.GA66984@owl.midgard.homeip.net> In-Reply-To: <20080610145926.GA66984@owl.midgard.homeip.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org, DA Forsyth Subject: Re: xRAID disks.... X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Jun 2008 15:09:29 -0000 Erik Trulsson wrote: > On Tue, Jun 10, 2008 at 04:33:47PM +0200, DA Forsyth wrote: > >> Hiya >> >> I've had this for a while now and have done many searches for info >> but have not yet come up with the right question, hence have not got >> the answer. >> >> My main server has an Adaptec IDE raid card. A couple of years ago I >> took disks that had been a mirror pair on that card out of the server >> and put them into my test server, not as a raid pair since the test >> server has no raid hardware. >> >> During boot I see this >> ad0: 19092MB at ata0-master UDMA66 >> ad1: 76319MB at ata0-slave UDMA66 >> ad2: 76319MB at ata1-master UDMA66 >> ad3: 19092MB at ata1-slave UDMA66 >> ar0: 76319MB status: BROKEN >> ar0: disk0 DOWN no device found for this subdisk >> ar0: disk1 DOWN no device found for this subdisk >> >> The pair of ex-RAID disks are ad1 and ad2 and obviously are no longer >> a raid pair, yet 'something' is telling the ar() driver to try and >> pair them and failing because there is no raid hardware in that box. >> >> Now I am reconfiguring that machine a bit and would like to fix this, >> both on these existing drives and on the 320MB drive I have just >> removed from a RAID1 pair and will be putting into the box instead of >> ad3 (the other 320GB from the pair is in a USB enclosure for other >> purposes and has not shown any signs of knowing it was in a raid >> pair) >> >> I suspect the raidinfo is stored on the disk somewhere and a suitable >> 'dd' command can erase it. but where and how? >> > > That kind of information is usually stored last on the disk (where it is > least likely to be overwritten by filesystems, partitioning info, or boot > loaders), so if you overwrite the last couple of KBs on those disks you will > probably be fine. > (If you want to be certain you can always use 'dd' to nuke all the > information on the disk. That will take longer time, but you get the extra > advantage of testing all the blocks on the disk so that they work > correctly.) > > For the first you could do something like: > dd if=/dev/zero of=/dev/ad1 bs=1m skip=76318 > which should overwrite the last MB of ad1 with zeros. > > To erase all of the disk: > dd if=/dev/zero of=/dev/ad1 bs=1m > > > I recently removed one pair of disks from a windows "hardware :)" RAID controller, and upon inserting it into a newly built FreeBSD system, it was immediately detected by the ar driver, and messages started coming in, like in your case. Although I ended up removing the ar device from the kernel (I was going to use gmirror), I found out that there is possibly another way to make the disks forget about their previous RAID-life: atacontrol delete ar0 Have a look at man atacontrol. I have not tried it, but it is probably worth a try.