From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx15.extmail.prod.ext.phx2.redhat.com [10.5.110.20]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s8MMG8j9025662 for ; Mon, 22 Sep 2014 18:16:08 -0400 Received: from mail1.bemta7.messagelabs.com (mail1.bemta7.messagelabs.com [216.82.254.97]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s8MMFtFu026612 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL) for ; Mon, 22 Sep 2014 18:15:56 -0400 From: Robb Walker Date: Mon, 22 Sep 2014 22:15:52 +0000 Message-ID: <1411424085397.51396@DRWHoldings.com> References: <1410908945365.65274@DRWHoldings.com> In-Reply-To: <1410908945365.65274@DRWHoldings.com> Content-Language: en-US MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [linux-lvm] lvm thin provisioning snapshots and btrfs Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: "linux-lvm@redhat.com" Also see the same results on ubu 14.04.1 lvm thin provisioning + btrfs. haven't tried arch 3.16 kernel and tools yet Robb Walker Linux/Unix Services Desk (312)542-2361 ~ Mobile (312)804-6034 Email: rwalker@drw.com DRW Holdings, LLC ~ 540 West Madison St. Chicago, IL 60661 ________________________________________ From: linux-lvm-bounces@redhat.com on behalf of Robb Walker Sent: Tuesday, September 16, 2014 6:10 PM To: linux-lvm@redhat.com Subject: [linux-lvm] lvm thin provisioning snapshots and btrfs Has anyone used lvm thin prov + btrfs on rhel/cent6u5? The build I am using off base iso with updates thru end feb 2014 so I have not yet applied all updates. However from rhel alerts I see no specific fixes for lvm or btrfs from that date forward. Unless I missed something. With lvm thin prov + ext4 I get expected results. When I take a snapshot. I see the snapshot is the state of the lvm volume at the point of time of snapshot creation. For btrfs, I am using a root subvolume mounted as @foo_root with a thinly provisioned lvm underneath. Same setup just using btrfs. I take a thin snapshot lvcreate -n lv_root_thin -s vg_thin/lv_root snapshot is created activate with lvchange -Kay /dev/vg_thin/lv_root_thin I then mount the snap with mount -odefaults,subvol=@foo_root /dev/vg_thin/lv_root_thin /snaps The contents match the origin lvm. Both lvms, origin and snap stay in sync with whatever changes I make. At one point I thought that maybe it was snapping at the subv level so I decided a snapshot of the root vol. However the deletion also appeared in the thin snapshot Also couple notes: I never see in lvs that the thin snapshot goes -o- online as I do in ext4 chdir into the /snaps and running df -h . shows that I'm in the snapshot chdir into /snaps/\@foo_root and running df -h . shows I'm in the origin vol.