This warning is still appearing in ubuntu 18.04, it seems indeed to be related to my partitionless PV as the message doesn't appear when i pull it out of the VG $ lsb_release -rd Description: Ubuntu 18.04.3 LTS Release: 18.04 $ apt-cache policy grub-common grub-common: Installé : 2.02-2ubuntu8.14 Candidat : 2.02-2ubuntu8.14 Table de version : *** 2.02-2ubuntu8.14 500 500 http://fr.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages 100 /var/lib/dpkg/status 2.02-2ubuntu8 500 500 http://fr.archive.ubuntu.com/ubuntu bionic/main amd64 Packages $ df -h Sys. de fichiers Taille Utilisé Dispo Uti% Monté sur udev 16G 0 16G 0% /dev tmpfs 3,2G 1,8M 3,2G 1% /run /dev/mapper/ubuntu--vg-root 98G 8,4G 85G 9% / tmpfs 16G 82M 16G 1% /dev/shm tmpfs 5,0M 4,0K 5,0M 1% /run/lock tmpfs 16G 0 16G 0% /sys/fs/cgroup /dev/loop0 4,3M 4,3M 0 100% /snap/gnome-calculator/544 /dev/loop1 1,0M 1,0M 0 100% /snap/gnome-logs/81 /dev/loop3 1,0M 1,0M 0 100% /snap/gnome-logs/61 /dev/loop2 15M 15M 0 100% /snap/gnome-characters/399 /dev/loop4 143M 143M 0 100% /snap/slack/21 /dev/loop5 55M 55M 0 100% /snap/core18/1668 /dev/loop6 55M 55M 0 100% /snap/core18/1066 /dev/loop8 150M 150M 0 100% /snap/gnome-3-28-1804/67 /dev/loop10 43M 43M 0 100% /snap/gtk-common-themes/1313 /dev/loop11 15M 15M 0 100% /snap/gnome-characters/296 /dev/loop7 45M 45M 0 100% /snap/gtk-common-themes/1440 /dev/loop16 92M 92M 0 100% /snap/core/8689 /dev/loop17 3,8M 3,8M 0 100% /snap/gnome-system-monitor/100 /dev/loop12 4,2M 4,2M 0 100% /snap/gnome-calculator/406 /dev/loop14 89M 89M 0 100% /snap/core/7270 /dev/loop9 161M 161M 0 100% /snap/gnome-3-28-1804/116 /dev/loop15 3,8M 3,8M 0 100% /snap/gnome-system-monitor/127 /dev/sda1 40M 12M 28M 30% /boot/efi /dev/mapper/ubuntu--vg-home 482G 21G 436G 5% /home /dev/mapper/ubuntu--vg-isos 9,8G 5,0G 4,3G 54% /isos tmpfs 3,2G 20K 3,2G 1% /run/user/1000 $ sudo pvdisplay --- Physical volume --- PV Name /dev/sda3 VG Name ubuntu-vg PV Size 635,26 GiB / not usable 3,00 MiB Allocatable yes PE Size 4,00 MiB Total PE 162627 Free PE 9027 Allocated PE 153600 PV UUID 6JNPjc-KHGn-A7jA-YPlW-bjz5-07se-xJfSfL --- Physical volume --- PV Name /dev/nvme0n1 VG Name ubuntu-vg PV Size <476,94 GiB / not usable <2,34 MiB Allocatable yes PE Size 4,00 MiB Total PE 122096 Free PE 122096 Allocated PE 0 PV UUID 68KCd3-XKws-rRoN-O8bN-sWGk-szly-JTHlLE $ sudo vgdisplay --- Volume group --- VG Name ubuntu-vg System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 11 VG Access read/write VG Status resizable MAX LV 0 Cur LV 3 Open LV 3 Max PV 0 Cur PV 2 Act PV 2 VG Size <1,09 TiB PE Size 4,00 MiB Total PE 284723 Alloc PE / Size 153600 / 600,00 GiB Free PE / Size 131123 / <512,20 GiB VG UUID 8EcqiN-e4Ct-PA38-gotJ-c1yp-Q0z1-Z3nza9 $ sudo lvdisplay --- Logical volume --- LV Path /dev/ubuntu-vg/root LV Name root VG Name ubuntu-vg LV UUID k45ZPQ-dncw-IRad-2oFU-hg0T-hVAF-cA3nnC LV Write Access read/write LV Creation host, time ubuntu, 2020-02-28 12:09:45 +0100 LV Status available # open 1 LV Size 100,00 GiB Current LE 25600 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0 --- Logical volume --- LV Path /dev/ubuntu-vg/home LV Name home VG Name ubuntu-vg LV UUID SHKebp-rI4x-tB92-LSJX-6p0V-8ygF-JvGK1m LV Write Access read/write LV Creation host, time ubuntu, 2020-02-28 12:11:55 +0100 LV Status available # open 1 LV Size 490,00 GiB Current LE 125440 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:1 --- Logical volume --- LV Path /dev/ubuntu-vg/isos LV Name isos VG Name ubuntu-vg LV UUID duK53O-zdbb-CUbd-He4r-UdAC-WDdL-1XMZ1Q LV Write Access read/write LV Creation host, time ubuntu, 2020-03-02 11:20:39 +0100 LV Status available # open 1 LV Size 10,00 GiB Current LE 2560 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:2