Public bug reported: [Impact]
On xenial with lvm2 2.02.133-1ubuntu10, if you say take a snapshot of a disk with an active VG, and attach that disk to the host, the VG will swap from the existing disk to the newly attached disk. This breaks mountpoints and directs writes to the wrong storage device. Note this only happens in the edge case where the PV and VGs are absolute duplicates. [Test] Steps to reproduce: 1) Create a xenial instance. 2) Create a secondary disk and attach it. 3) Create a PV, VG and LV on the disk. 4) Run lsblk: ubuntu@ubuntu:~$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT vdb 253:16 0 2G 0 disk └─test1-database 252:0 0 1.6G 0 lvm /mnt/database 5) Create a "snapshot" of this disk (cp -rp disk.qcow2 disk2.qcow2) 6) Attach disk2.qcow2. Check lsblk ubuntu@ubuntu:~$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT vdb 253:16 0 2G 0 disk vdc 253:32 0 2G 0 disk └─test1-database 252:0 0 1.6G 0 lvm We can see the VG jumps from /dev/vdb to /dev/vdc, even though the system was running at the time, and the VG was mounted. [Regression Potential] The risk of regression if we fix this issue is extreme. The commits themselves are large and modify core LVM code, and change the behaviour of how disks are scanned and processed. The commits introduce new configuration options. The commits do not apply cleanly, and all of them require significant backporting, and quite a few dependencies. Because of this, it would be far too risky to fix this for xenial, so I will mark this as wontfix. [Other Info] This was fixed in 2.02.153 by the following commits: commit 49d9582bed338dc555b616bcc9de20fafd00ce2d Author: David Teigland <teigl...@redhat.com> Date: Tue Mar 29 13:29:39 2016 -0500 Subject: lvmcache: use active LVs and device sizes to choose between duplicates Link: https://github.com/lvmteam/lvm2/commit/49d9582bed338dc555b616bcc9de20fafd00ce2d commit d4e434d1e6082ff4d448f4fbc03962c6f0926da4 Author: David Teigland <teigl...@redhat.com> Date: Fri Apr 29 14:42:14 2016 -0500 Subject: pvs: new attr and field for unchosen duplicate device Link: https://github.com/lvmteam/lvm2/commit/d4e434d1e6082ff4d448f4fbc03962c6f0926da4 commit d3d13e134af15611c3f12107aa1627b12110a974 Author: David Teigland <teigl...@redhat.com> Date: Thu Feb 11 12:37:36 2016 -0600 Subject: lvmcache: process duplicate PVs directly Link: https://github.com/lvmteam/lvm2/commit/d3d13e134af15611c3f12107aa1627b12110a974 commit 8b7a78c728be3b9af698dae9344d01752c4cf615 Author: David Teigland <teigl...@redhat.com> Date: Tue Feb 9 13:06:27 2016 -0600 Subject: lvmcache: improve duplicate PV handling Link: https://github.com/lvmteam/lvm2/commit/8b7a78c728be3b9af698dae9344d01752c4cf615 commit 3d2fbfe243550b7801165f393d27e35044c1a56d Author: David Teigland <teigl...@redhat.com> Date: Fri Jan 29 13:31:54 2016 -0600 Subject: lvmetad: set disabled flag when duplicate PVs are seen Link: https://github.com/lvmteam/lvm2/commit/3d2fbfe243550b7801165f393d27e35044c1a56d commit 9539ee809827a870c88d02cfb2d0dc1e3eaac0d0 Author: David Teigland <teigl...@redhat.com> Date: Fri Jan 29 12:25:20 2016 -0600 Subject: lvmetad: set disabled flag in lvmetad if duplicate PVs are found Link: https://github.com/lvmteam/lvm2/commit/9539ee809827a870c88d02cfb2d0dc1e3eaac0d0 The fixes are present in Ubuntu 16.10 and later, meaning xenial is the only impacted supported release. ** Affects: lvm2 (Ubuntu) Importance: Undecided Status: Fix Released ** Affects: lvm2 (Ubuntu Xenial) Importance: Medium Assignee: Matthew Ruffell (mruffell) Status: Won't Fix ** Affects: lvm2 (Ubuntu Bionic) Importance: Undecided Status: Fix Released ** Affects: lvm2 (Ubuntu Disco) Importance: Undecided Status: Fix Released ** Affects: lvm2 (Ubuntu Eoan) Importance: Undecided Status: Fix Released ** Affects: lvm2 (Ubuntu Focal) Importance: Undecided Status: Fix Released ** Tags: sts ** Also affects: lvm2 (Ubuntu Xenial) Importance: Undecided Status: New ** Also affects: lvm2 (Ubuntu Bionic) Importance: Undecided Status: New ** Also affects: lvm2 (Ubuntu Disco) Importance: Undecided Status: New ** Also affects: lvm2 (Ubuntu Focal) Importance: Undecided Status: New ** Also affects: lvm2 (Ubuntu Eoan) Importance: Undecided Status: New ** Changed in: lvm2 (Ubuntu Bionic) Status: New => Fix Released ** Changed in: lvm2 (Ubuntu Disco) Status: New => Fix Released ** Changed in: lvm2 (Ubuntu Eoan) Status: New => Fix Released ** Changed in: lvm2 (Ubuntu Focal) Status: New => Fix Released ** Changed in: lvm2 (Ubuntu Xenial) Status: New => Won't Fix ** Changed in: lvm2 (Ubuntu Xenial) Importance: Undecided => Medium ** Changed in: lvm2 (Ubuntu Xenial) Assignee: (unassigned) => Matthew Ruffell (mruffell) ** Tags added: sts -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1869831 Title: lvm2: VG swaps to most recent disk if underlying PV has duplicate UUID and VG name To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lvm2/+bug/1869831/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
