From owner-freebsd-questions@FreeBSD.ORG  Mon Mar  3 23:47:51 2014
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 398C5F24
 for <freebsd-questions@freebsd.org>; Mon,  3 Mar 2014 23:47:51 +0000 (UTC)
Received: from mail-ig0-x233.google.com (mail-ig0-x233.google.com
 [IPv6:2607:f8b0:4001:c05::233])
 (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits))
 (No client certificate requested)
 by mx1.freebsd.org (Postfix) with ESMTPS id 0D3E8104
 for <freebsd-questions@freebsd.org>; Mon,  3 Mar 2014 23:47:51 +0000 (UTC)
Received: by mail-ig0-f179.google.com with SMTP id t19so14997igi.0
 for <freebsd-questions@freebsd.org>; Mon, 03 Mar 2014 15:47:50 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
 h=mime-version:date:message-id:subject:from:to:content-type;
 bh=6Yi7HWYldLejQ1kDFf09fNSS6ARtIHZ4DgP6F4c1ekw=;
 b=BWOTgAGMBCtpkD/XosJ0T2kOfHNOX/691NWK8gtcwb4l0HrjQRjZDU3cL1RqYyx4wh
 /YEBNFNSHK9qND7C+OMUkcHRp9YztKWrtzSdot9idrJB4hdxEpfeaBQrAFBN6jTWmlqo
 Ja7cZqv9LGSWXcRYMuqAMO5ZjcId67NFd8pDOoHl37fRIiuRFxxlB4SeVUbECKwitYI6
 ZUuyxuxm+LKYcQQ3r3GWXwjWso2JjWvo68Pl8Q0yFd0EwAWggB/VS+HF/uhQlhcXOiT+
 R7PLpQxVAEWMBKT9j9lWY6iCG+VMLNBpOUSMG+8Rd2eMW/LV37x+YeHNV9rxvg9iLlK1
 XAKQ==
MIME-Version: 1.0
X-Received: by 10.50.225.65 with SMTP id ri1mr31278862igc.1.1393890470197;
 Mon, 03 Mar 2014 15:47:50 -0800 (PST)
Received: by 10.43.157.66 with HTTP; Mon, 3 Mar 2014 15:47:50 -0800 (PST)
Date: Mon, 3 Mar 2014 15:47:50 -0800
Message-ID: <CAPi0psuD5zDBuBZmE3tBKDeFdMcpvBn3pU4waDu6FU8SaTs0-Q@mail.gmail.com>
Subject: ZFS, GPTIDs, and using the whole disk
From: Chris Stankevitz <chrisstankevitz@gmail.com>
To: freebsd-questions <freebsd-questions@freebsd.org>
Content-Type: text/plain; charset=ISO-8859-1
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://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: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 03 Mar 2014 23:47:51 -0000

Please identify any false statements:

1. ZFS prefers to use the entire disk.

2. The only way to refer to an entire disk is by the device name e.g. /dev/da4

3. Device names like /dev/da4 are not persistently connected to actual
SATA ports on your motherboard/expander.  For example, if you start
hot swapping disks, even if you put them back in the same slot, their
device names might change.  Even if you don't hot swap, the device
name for a particular disk might change for other reasons (e.g. if you
have a USB drive plugged in during boot).

4. Because of (3) it is dangerous to use device names when building a zpool

5. GPTIDs are persistently attached to physical drives.

5a. This is because the GPTID is written on the disk when you create the GPTID.

6. A GPTID does not refer to an entire disk.

6a. A GPTID refers to a partition

7. You can create a zpool of GPTIDs

8. A zpool created from GPTIDs will not be using the entire disk.

9. You cannot simultaneously allow ZFS access to the entire disk while
keeping persistent names/labels.

Thank you,

Chris