From owner-freebsd-fs@FreeBSD.ORG  Thu Jun 18 22:56:20 2009
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
Delivered-To: freebsd-fs@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id A14701065715
	for <freebsd-fs@freebsd.org>; Thu, 18 Jun 2009 22:56:20 +0000 (UTC)
	(envelope-from andrew@modulus.org)
Received: from email.octopus.com.au (email.octopus.com.au [122.100.2.232])
	by mx1.freebsd.org (Postfix) with ESMTP id 61DC18FC1A
	for <freebsd-fs@freebsd.org>; Thu, 18 Jun 2009 22:56:20 +0000 (UTC)
	(envelope-from andrew@modulus.org)
Received: by email.octopus.com.au (Postfix, from userid 1002)
	id E94F217409; Fri, 19 Jun 2009 08:56:42 +1000 (EST)
X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on email.octopus.com.au
X-Spam-Level: 
X-Spam-Status: No, score=-1.4 required=10.0 tests=ALL_TRUSTED autolearn=failed
	version=3.2.3
Received: from [10.1.50.60] (ppp121-44-41-14.lns10.syd7.internode.on.net
	[121.44.41.14])
	(using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
	(No client certificate requested)
	(Authenticated sender: admin@email.octopus.com.au)
	by email.octopus.com.au (Postfix) with ESMTP id 0210417428;
	Fri, 19 Jun 2009 08:56:38 +1000 (EST)
Message-ID: <4A3AC5B2.9010607@modulus.org>
Date: Fri, 19 Jun 2009 08:54:42 +1000
From: Andrew Snow <andrew@modulus.org>
User-Agent: Thunderbird 2.0.0.14 (X11/20080523)
MIME-Version: 1.0
To: Randy Bush <randy@psg.com>
References: <m2bpol6v8r.wl%randy@psg.com>	<4A3ABF76.3020905@modulus.org>	<cf9b1ee00906181540w746edafi4a560b0925b14e27@mail.gmail.com>
	<m28wjp6tp2.wl%randy@psg.com>
In-Reply-To: <m28wjp6tp2.wl%randy@psg.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: freebsd-fs@freebsd.org
Subject: Re: adding drive to raidz1
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 18 Jun 2009 22:56:21 -0000


> 	    NAME        STATE     READ WRITE CKSUM
> 	    tank        ONLINE       0     0     0
> 	      raidz1    ONLINE       0     0     0
> 		ad4s3   ONLINE       0     0     0
> 		ad5s3   ONLINE       0     0     0
> 		ad6s1   ONLINE       0     0     0
> 	      ad7s1     ONLINE       0     0     0

Here you have created a non-redundant stripe with two vdev members:
1.  a 3-disk RAIDZ1 and
2.a single disk.

So you can't ever remove the ad7s1 without data loss.

If you haven't written anything to the pool since adding ad7s1, you can 
probably yank the disk out and ignore any errors but the error messages 
will never go away until you recreate the whole pool from scratch