From owner-freebsd-questions@freebsd.org  Wed May 11 22:27:08 2016
Return-Path: <owner-freebsd-questions@freebsd.org>
Delivered-To: freebsd-questions@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5208DB384CC
 for <freebsd-questions@mailman.ysv.freebsd.org>;
 Wed, 11 May 2016 22:27:08 +0000 (UTC)
 (envelope-from list_freebsd@bluerosetech.com)
Received: from echo.brtsvcs.net (echo.brtsvcs.net [IPv6:2607:f740:c::4ae])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 405B51CA9
 for <freebsd-questions@freebsd.org>; Wed, 11 May 2016 22:27:08 +0000 (UTC)
 (envelope-from list_freebsd@bluerosetech.com)
Received: from chombo.houseloki.net (unknown
 [IPv6:2601:1c2:1402:3a86:21c:c0ff:fe7f:96ee])
 by echo.brtsvcs.net (Postfix) with ESMTPS id 4E54E3802C;
 Wed, 11 May 2016 22:27:07 +0000 (UTC)
Received: from [IPv6:2601:1c2:1402:3a86:92b1:1cff:fea6:3e5d] (unknown
 [IPv6:2601:1c2:1402:3a86:92b1:1cff:fea6:3e5d])
 by chombo.houseloki.net (Postfix) with ESMTPSA id 8F4889D7;
 Wed, 11 May 2016 15:27:06 -0700 (PDT)
Subject: Re: FreeBSD-10.3 root ZFS redux
To: Graham Allan <allan@physics.umn.edu>, freebsd-questions@freebsd.org
References: <0409d2208ccce8e2f9e0ce6526bf6756.squirrel@webmail.harte-lyne.ca>
 <5845c9cfc3bed4171df9b4b386573782.squirrel@webmail.harte-lyne.ca>
 <573377D4.7080909@physics.umn.edu>
From: Mel Pilgrim <list_freebsd@bluerosetech.com>
Reply-To: freebsd-questions@freebsd.org
Message-ID: <3b96335d-d1cd-4a88-bbe2-457c4379d9df@bluerosetech.com>
Date: Wed, 11 May 2016 15:27:12 -0700
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101
 Thunderbird/45.0
MIME-Version: 1.0
In-Reply-To: <573377D4.7080909@physics.umn.edu>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions/>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 11 May 2016 22:27:08 -0000

On 5/11/2016 11:20 AM, Graham Allan wrote:
> On 5/11/2016 1:13 PM, James B. Byrne wrote:
>>
>> I managed to get this reversed in my head as I composed.  The question
>> is what happens when a nominally 3TB HDD is put in that has fewer
>> accessible sectors than a similar 3TB drive already present?
>
> My understanding is that it would just be rejected (I see some older
> solaris examples mention a "device too small" error).
>
> Best practice is probably to create a gpt partition of some standard
> size on the drives before adding that to the pool, to give a little
> adjustment room, though I confess I have made all my pools to date using
> the raw drives (other than a geom label); and simply try to replace
> drives with the same model.

You need to do this anyway for root on ZFS without other storage in the 
system because of the freebsd-boot partition.