From owner-freebsd-fs@freebsd.org Tue Sep 22 14:42:08 2015 Return-Path: Delivered-To: freebsd-fs@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 13B6EA077D2 for ; Tue, 22 Sep 2015 14:42:08 +0000 (UTC) (envelope-from wblock@wonkity.com) Received: from wonkity.com (wonkity.com [67.158.26.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "wonkity.com", Issuer "wonkity.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id C72CC152B for ; Tue, 22 Sep 2015 14:42:07 +0000 (UTC) (envelope-from wblock@wonkity.com) Received: from wonkity.com (localhost [127.0.0.1]) by wonkity.com (8.15.2/8.15.2) with ESMTPS id t8MEg56B044977 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 22 Sep 2015 08:42:05 -0600 (MDT) (envelope-from wblock@wonkity.com) Received: from localhost (wblock@localhost) by wonkity.com (8.15.2/8.15.2/Submit) with ESMTP id t8MEg5RK044974; Tue, 22 Sep 2015 08:42:05 -0600 (MDT) (envelope-from wblock@wonkity.com) Date: Tue, 22 Sep 2015 08:42:05 -0600 (MDT) From: Warren Block To: Chris Stankevitz cc: FreeBSD Filesystems Subject: Re: Name/label/id metadata: how do I make it go away In-Reply-To: <5600F0DF.8000805@stankevitz.com> Message-ID: References: <56004C68.4020904@stankevitz.com> <5600F0DF.8000805@stankevitz.com> User-Agent: Alpine 2.20 (BSF 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (wonkity.com [127.0.0.1]); Tue, 22 Sep 2015 08:42:05 -0600 (MDT) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Sep 2015 14:42:08 -0000 On Mon, 21 Sep 2015, Chris Stankevitz wrote: > Warren/Freddie, > > Thank you for your replies. > > On 9/21/15 8:41 PM, Warren Block wrote: >>> - gpt id >> >> A system-assigned ID in the GPT metadata. Requires GPT partitioning. ZFS on bare devices uses an EFI label that is similar or related to GPT. Those might be detected and displayed even without GPT, but I'm not sure. >>> I have a zfs pool of "entire disks". "zpool status" shows some disks >>> with their daX name (which I prefer) and some with a hideously ugly >>> name such as DISK-%20%20%20%20%20-WD-WMC4NOH1ASDF >> >> Disable those labels with kern.geom.label.gptid.enable="0" in >> /boot/loader.conf. > > Combining your two statements quoted above, I believe I can conclude that my > ZFS "whole disk" drives must have some remnants of GPT left over from their > previous lives (namely the system-assigned ID in the GPT metadata). > > Surprisingly, these apparently GPT-supplied labels appear to "go away" when I > issue a "glabel stop". I would not expect this given that Warren explained > that glabels (whose metadata are stored at the end of the device and > completely outside the virtual device) are not the same as GPT labels (whose > metadata are stored within the device on the GPT metadata). "glabel" is both a command that creates manual labels and a GEOM class that creates the entries in /dev when device labels of all types are found. Stopping the label class stops the display of all labels. glabel(8) is worth the read.