From owner-freebsd-geom@FreeBSD.ORG  Tue Jun 17 16:40:04 2008
Return-Path: <owner-freebsd-geom@FreeBSD.ORG>
Delivered-To: freebsd-geom@hub.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 219F91065673
	for <freebsd-geom@hub.freebsd.org>;
	Tue, 17 Jun 2008 16:40:04 +0000 (UTC)
	(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (freefall.freebsd.org
	[IPv6:2001:4f8:fff6::28])
	by mx1.freebsd.org (Postfix) with ESMTP id 096C38FC28
	for <freebsd-geom@hub.freebsd.org>;
	Tue, 17 Jun 2008 16:40:04 +0000 (UTC)
	(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1])
	by freefall.freebsd.org (8.14.2/8.14.2) with ESMTP id m5HGe3Oq068551
	for <freebsd-geom@freefall.freebsd.org>; Tue, 17 Jun 2008 16:40:03 GMT
	(envelope-from gnats@freefall.freebsd.org)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.14.2/8.14.1/Submit) id m5HGe3mP068550;
	Tue, 17 Jun 2008 16:40:03 GMT (envelope-from gnats)
Date: Tue, 17 Jun 2008 16:40:03 GMT
Message-Id: <200806171640.m5HGe3mP068550@freefall.freebsd.org>
To: freebsd-geom@FreeBSD.org
From: Ulf Lilleengen <lulf@stud.ntnu.no>
Cc: 
Subject: Re: kern/124294: [geom] gmirror(8) have inappropriate logic when
	working with bad hard-drive
X-BeenThere: freebsd-geom@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
Reply-To: Ulf Lilleengen <lulf@stud.ntnu.no>
List-Id: GEOM-specific discussions and implementations
	<freebsd-geom.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-geom>,
	<mailto:freebsd-geom-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-geom>
List-Post: <mailto:freebsd-geom@freebsd.org>
List-Help: <mailto:freebsd-geom-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-geom>,
	<mailto:freebsd-geom-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 17 Jun 2008 16:40:04 -0000

The following reply was made to PR kern/124294; it has been noted by GNATS.

From: Ulf Lilleengen <lulf@stud.ntnu.no>
To: bug-followup@FreeBSD.org, dindin@dindin.ru
Cc:  
Subject: Re: kern/124294: [geom] gmirror(8) have inappropriate logic when
	working with bad hard-drive
Date: Tue, 17 Jun 2008 18:30:29 +0200

 When presented two drives with equal or different content, gmirror have no
 way to know which drive is good.  As far as gmirror is concerned, as long as
 the metadata is ok, the content should be as well. To avoid this, one could
 use ZFS or geli to verify the integrity of the data.
 
 However, perhaps one way to avoid this would be to prevent gmirror to sync
 from a disk which is has booted from. However, even if the boot succeeds and the good
 disk is not synced with corrupted data, there is no guarantee that other
 parts of the disk that you booted from is good, so you might be assuming you
 have a good disk, but you're really booting from a bad one.
 
 Any suggestions?
 
 -- 
 Ulf Lilleengen