From owner-freebsd-fs@freebsd.org Tue Sep 22 21:43:35 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 A99ABA06D35 for ; Tue, 22 Sep 2015 21:43:35 +0000 (UTC) (envelope-from chris@stankevitz.com) Received: from mango.stankevitz.com (mango.stankevitz.com [208.79.93.194]) by mx1.freebsd.org (Postfix) with ESMTP id 94F6E1151 for ; Tue, 22 Sep 2015 21:43:35 +0000 (UTC) (envelope-from chris@stankevitz.com) Received: from Chriss-MacBook-Pro.local (209-203-101-124.static.twtelecom.net [209.203.101.124]) (using TLSv1.2 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mango.stankevitz.com (Postfix) with ESMTPSA id 33A9311E5; Tue, 22 Sep 2015 14:43:34 -0700 (PDT) Subject: Re: Name/label/id metadata: how do I make it go away To: Warren Block References: <56004C68.4020904@stankevitz.com> <5600F0DF.8000805@stankevitz.com> <5601A82A.7040304@stankevitz.com> <5601B2AF.7040306@stankevitz.com> Cc: Matt Churchyard , FreeBSD FS From: Chris Stankevitz Message-ID: <5601CB85.8070400@stankevitz.com> Date: Tue, 22 Sep 2015 14:43:33 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit 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 21:43:35 -0000 On 9/22/15 2:01 PM, Warren Block wrote: >> According to 'geom disk list', each of my 22 drives has an "ident", >> but only some of them have "labels". >> >> "ident" is turned into a "label" via a process called "tasting": >> sys/geom/label/g_label_disk_ident.c >> sys/geom/label/g_label.c >> >> Although it is not yet clear to me why apparently only some of my >> disks are "tasted". > > Labels on devices that are mounted are "withered" and disappear. Thank you. Indeed when I export the pool, all of the drives become listed in /dev/diskid. When I re-import the pool, some of the drives "wither" and are removed from /dev/diskid. These withered drives appear as daX in "zpool status". The drives that do not wither remain in /dev/diskid and appear in "zpool status" with their /dev/diskid/X names. Q: Why do my identical zpool drives behave differently? Please let me know if my hypothesis is plausible: ZFS sees both the /dev/daX "consumers" and the /dev/diskid/X "providers". ZFS is randomly selecting which to use to import the pool. Sometimes it picks "consumers" and sometimes "providers". When ZFS picks a consumer, the provider is withered away. When ZFS picks a provider, the provider remains. And if I want to dig deeper into root cause I can ask ZFS "why do you sometimes select from the consumer collection and sometimes from the provider collection when putting a pool together". Or if I don't want to dig deeper I can "deal with it" or I can disable diskid using kern.geom.label.disk_ident.enable Thank you again, Chris