From owner-freebsd-questions@freebsd.org Wed Sep 23 17:07:55 2015 Return-Path: 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 975E8A0790F for ; Wed, 23 Sep 2015 17:07:55 +0000 (UTC) (envelope-from paul@kraus-haus.org) Received: from mail-qg0-f50.google.com (mail-qg0-f50.google.com [209.85.192.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 579F31994 for ; Wed, 23 Sep 2015 17:07:54 +0000 (UTC) (envelope-from paul@kraus-haus.org) Received: by qgev79 with SMTP id v79so24497413qge.0 for ; Wed, 23 Sep 2015 10:07:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:content-type:mime-version:subject:from :in-reply-to:date:content-transfer-encoding:message-id:references:to; bh=HHFQEINQgoD2lEw8/6dCWVsNRzIfg1JZv1RSgynHLCo=; b=m4kQqxMzTTlWhJa/p4nmV3mG4tBdOX157/Z52so74P36pgG1nBwHZaGw/Unem5n+86 PzOsFV2HKWrDUTmN+YBdISCSF/VVTjIkMch020kjBd8IeT0oC4iJW3yVqstFpjVeoK/3 SHezwVfXXU+v4ZzluV7kaV/XPGG4W4+ymK5yhJeMZq3+i3Q3VxlmD1mo5gCtYHR40Skc IGk6vzuwWzoSRx240BFBgJRy0OQ+r+LMg1TxSwEAF0fLg7onn2HRK/J8s+JXW2+gajTa 1pweq9MBcrG5emkEKHHuuGYV8YQtH6CTKEsBrCRJDZ1wpU+TNqSCHhxk1jJpKS1+41TV 9DRg== X-Gm-Message-State: ALoCoQktpCHgExhTshAYsXW7x2RckHWpg+3x/4CoqGErV6Q7eiNLx7eLobhw9Ap3tqujJzBZk0dz X-Received: by 10.140.96.200 with SMTP id k66mr37328549qge.81.1443028074154; Wed, 23 Sep 2015 10:07:54 -0700 (PDT) Received: from mbp-1.thecreativeadvantage.com (mail.thecreativeadvantage.com. [96.236.20.34]) by smtp.gmail.com with ESMTPSA id g82sm2842366qhc.32.2015.09.23.10.07.52 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 23 Sep 2015 10:07:52 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Subject: Re: Name/label/id metadata: how do I make it go away From: Paul Kraus In-Reply-To: <5601CB85.8070400@stankevitz.com> Date: Wed, 23 Sep 2015 13:07:49 -0400 Content-Transfer-Encoding: quoted-printable Message-Id: <93BD5F1D-9A64-4430-8519-FCF71E817A29@kraus-haus.org> References: <56004C68.4020904@stankevitz.com> <5600F0DF.8000805@stankevitz.com> <5601A82A.7040304@stankevitz.com> <5601B2AF.7040306@stankevitz.com> <5601CB85.8070400@stankevitz.com> To: Chris Stankevitz , FreeBSD Questions X-Mailer: Apple Mail (2.1878.6) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Sep 2015 17:07:55 -0000 On Sep 22, 2015, at 17:43, Chris Stankevitz = wrote: > 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 Assuming 10.x, on boot the ZFS code scans all attached devices and = attempts to reassemble any zpools that it finds that were owned by this = system. I suspect which device ZFS uses is based on which it scans (and = finds) first. I actually prefer the /dev/diskid/nnn names as those are tied to the = physical drives. By using them I guarantee that even if a drive = physically (or logically if drives or controllers are added) moves the = system can still find and import the zpool. In the early days of ZFS one = of the best ways to damage a zpool was to rearrange drives so that the = ZFS label (and cache) no longer agreed with reality. I was in the habit = of manually exporting critical zpools before making any hardware changes = and after the changes were complete I would import the pool (sometime = with new device names). ZFS _should_ be robust enough to handle device = movement today, but I am slightly paranoid when it comes to critical = data. -- Paul Kraus paul@kraus-haus.org