From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from resqmta-ch2-08v.sys.comcast.net ([69.252.207.40]:41357 "EHLO resqmta-ch2-08v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932285AbaKSB3Q (ORCPT ); Tue, 18 Nov 2014 20:29:16 -0500 Message-ID: <546BF268.5050706@pobox.com> Date: Tue, 18 Nov 2014 17:29:12 -0800 From: Robert White MIME-Version: 1.0 To: Phillip Susi , Chris Murphy CC: Btrfs BTRFS Subject: Re: BTRFS messes up snapshot LV with origin References: <54699CC7.1050909@swiftspirit.co.za> <546A46A5.8030603@inwind.it> <27BDAC3B-789C-4477-B065-E703CE425F54@colorremedies.com> <546B68F8.6080008@ubuntu.com> In-Reply-To: <546B68F8.6080008@ubuntu.com> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 11/18/2014 07:42 AM, Phillip Susi wrote: > On 11/18/2014 1:16 AM, Chris Murphy wrote: >> (stuff about UUIDs and LVM snapshots). > (suggestion to use LVM paths instead). This is also an XFS+LVM+LVM_Snapshot problem going back to at least 2009. It's inherent to the block-device-level snapshot phenomonia. q.v. http://www.miljan.org/main/2009/11/16/lvm-snapshots-and-xfs/ et al In XFS you attack the snapshot with a command to regenerate the UUID as soon as you take the snapshot. I don't think there is a "regenerate all my UUIDs" command for BTRFS. There are other places this can bone you, like old-format mdadm mirrors, where the metadata was only at the end of the partition so you could accidentally see two copied of your RAID1 file system if you hand't built/started the array. There is no really good way to prevent this other than "being really careful" or "not doing that at all". Sorry. Cost of doing business. Cheers... Rob.