IMHO thin-provisioning is an optional volumes type in LVM2 and is not required for operating LVM. The fact that lvconvert works to convert things to/from optionally supported types, is imho ok. In the same way we ship many tools that can convert formats but not necessarily open those for modification. E.g. i can use qemu-img to convert disk images to e.g. VMWare format but I might not have any hypervisor that knows how to boot such an image and allow to modify it (e.g. upgrade packages).
>From usability point of view, it might help if attempts to activate thin volumes should result in messaging like "maybe install packages foo bar?" Similar to how command-not-found operates. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to lvm2 in Ubuntu. https://bugs.launchpad.net/bugs/1657646 Title: Missing thin-provisioning-tools prevents VG with thin pool LV from being (de)activated, but not its creation Status in lvm2 package in Ubuntu: New Status in lvm2 package in Debian: New Bug description: Creating a thin pool LV is allowed even when thin-provisioning-tools is not installed. But deactivating or activating that VG fails. Since deactivating the VG usually only happens at reboot, the user might fail to notice this big problem until then. I think the lvconvert tool, used to combine the two "thin LVs" into a thin pool LV, should refuse to run if thin-provisioning-tools, or the needed scripts, aren't installed. Steps to reproduce: root@15-89:~# vgcreate vg /dev/vdb1 Volume group "vg" successfully created root@15-89:~# vgs VG #PV #LV #SN Attr VSize VFree vg 1 0 0 wz--n- 40.00g 40.00g root@15-89:~# lvcreate -n pool0 -l 90%VG vg Logical volume "pool0" created. root@15-89:~# lvcreate -n pool0meta -l 5%VG vg Logical volume "pool0meta" created. root@15-89:~# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert pool0 vg -wi-a----- 36.00g pool0meta vg -wi-a----- 2.00g root@15-89:~# ll /dev/mapper/ total 0 drwxr-xr-x 2 root root 100 Jun 21 14:15 ./ drwxr-xr-x 20 root root 3820 Jun 21 14:15 ../ crw------- 1 root root 10, 236 Jun 21 13:15 control lrwxrwxrwx 1 root root 7 Jun 21 14:14 vg-pool0 -> ../dm-0 lrwxrwxrwx 1 root root 7 Jun 21 14:15 vg-pool0meta -> ../dm-1 root@15-89:~# lvconvert --type thin-pool --poolmetadata vg/pool0meta vg/pool0 WARNING: Converting logical volume vg/pool0 and vg/pool0meta to pool's data and metadata volumes. THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.) Do you really want to convert vg/pool0 and vg/pool0meta? [y/n]: y Converted vg/pool0 to thin pool. root@15-89:~# ll /dev/mapper/ total 0 drwxr-xr-x 2 root root 120 Jun 21 14:15 ./ drwxr-xr-x 20 root root 3840 Jun 21 14:15 ../ crw------- 1 root root 10, 236 Jun 21 13:15 control lrwxrwxrwx 1 root root 7 Jun 21 14:15 vg-pool0 -> ../dm-2 lrwxrwxrwx 1 root root 7 Jun 21 14:15 vg-pool0_tdata -> ../dm-1 lrwxrwxrwx 1 root root 7 Jun 21 14:15 vg-pool0_tmeta -> ../dm-0 root@15-89:~# lvs -a LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%S ync Convert [lvol0_pmspare] vg ewi------- 2.00g pool0 vg twi-a-tz-- 36.00g 0.00 0.01 [pool0_tdata] vg Twi-ao---- 36.00g [pool0_tmeta] vg ewi-ao---- 2.00g If you now reboot the system, all that is gone: root@15-89:~# ll /dev/mapper/ total 0 drwxr-xr-x 2 root root 60 Jun 21 14:28 ./ drwxr-xr-x 19 root root 3760 Jun 21 14:28 ../ crw------- 1 root root 10, 236 Jun 21 14:28 control The same happens if you deactivate the VG (which the reboot undoubtedly triggers). It fails because of a missing /usr/sbin/thin_check which is provided by the thin-provisioning-tools package: root@15-89:~# vgchange -a n /usr/sbin/thin_check: execvp failed: No such file or directory WARNING: Integrity check of metadata for pool vg/pool0 failed. 0 logical volume(s) in volume group "vg" now active root@15-89:~# ll /dev/mapper/ total 0 drwxr-xr-x 2 root root 60 Jun 21 14:29 ./ drwxr-xr-x 19 root root 3760 Jun 21 14:29 ../ crw------- 1 root root 10, 236 Jun 21 14:28 control To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lvm2/+bug/1657646/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
