From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-33-i2.italiaonline.it ([212.48.25.204]:39631 "EHLO smtp-33.italiaonline.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751087AbaK2Het (ORCPT ); Sat, 29 Nov 2014 02:34:49 -0500 Message-ID: <5479774E.1050302@inwind.it> Date: Sat, 29 Nov 2014 08:35:42 +0100 From: Goffredo Baroncelli Reply-To: kreijack@inwind.it MIME-Version: 1.0 To: Robert White , Zygo Blaxell CC: linux-btrfs Subject: Re: BTRFS messes up snapshot LV with origin References: <2A57F99C-80AA-4FD4-AA41-57F02AD4E1A2@colorremedies.com> <546CB531.2060509@ubuntu.com> <20141121042814.GR17395@hungrycats.org> <5470C92E.1070607@inwind.it> <20141123001927.GO17380@hungrycats.org> <5474AF87.6090702@inwind.it> <20141125202948.GP17380@hungrycats.org> <5474FBD9.5070709@inwind.it> <20141125222126.GQ17380@hungrycats.org> <54760B89.3050604@inwind.it> <20141127041510.GV17380@hungrycats.org> <5478AB6C.7030809@inwind.it> <54792084.6060404@pobox.com> In-Reply-To: <54792084.6060404@pobox.com> Content-Type: text/plain; charset=windows-1252 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 11/29/2014 02:25 AM, Robert White wrote: > On 11/28/2014 09:05 AM, Goffredo Baroncelli wrote: >> For the disk autodetection, I still convinced that it is a "sane" >> default to skip the lvm-snapshot > > No... please don't... > > Maybe offer an option to select between snapshots or no-snapshots but > in much the same way there is no _functional_ difference between a > subvolume and a snapshot in btrfs, there is no "degenerate" status to > an LVM snapshot. I agree with you; but I have to find a "default" so during the boot a system can start even if snapshots are present. And pay attention that there would be cases where multiple snapshot are present: how group these ? My be for generation number ? Anyway for the moment my help simply refuse to mount if there is a conflict of dev_uuid. > > It would be way more useful if the helper dumped a message via stderr > or syslog that said something like "UUID=xxxxxxxx ambiguous, This is what it is printed when the helper finds a duplicate uuid: ghigo@emulato:~$ sudo lvdisplay | grep "LV Path" LV Path /dev/test/lv01 LV Path /dev/test/lv02 LV Path /dev/test/lv02_snap LV Path /dev/test/lv01_snap ghigo@emulato:~$ sudo mount /dev/test/lv01 /mnt/btrfs1/ ERROR: disk '/dev/mapper/test-lv01' and '/dev/mapper/test-lv01_snap' have the same disk uuid ERROR: disk '/dev/mapper/test-lv02_snap' and '/dev/mapper/test-lv02' have the same disk uuid > must > select between /dev/AA and /dev/BB using device= to mount > filesystem." But anyway I can force the disk to mount: ghigo@emulato:~$ sudo mount /dev/test/lv01_snap -o device=/dev/test/lv02_snap /mnt/btrfs1/ > > > -- gpg @keyserver.linux.it: Goffredo Baroncelli Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5