Indeed, the cmdline defines root=UUID=288689a9-116a-4867-93a2-75a963062c61 while /target/etc/fstab contains: /dev/disk/by-id/dm-uuid-LVM-wZilMCEJKlgdikVkEQdHhMiC8wYpJXVuDn9HuJvMYqYZu5DCbwb7nmGjMthndwJE After reboot, inside the initramfs, it isn't able to setup or find any LVM LVs or VGs and nothing which would contain this UUID. Some more information about the installed system, after installation, but before reboot (incl /etc/fstab): root@ubuntu-server:/# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT loop0 7:0 0 765M 1 loop /target/cdrom loop1 7:1 0 328.7M 1 loop /media/filesystem loop2 7:2 0 231.4M 1 loop loop3 7:3 0 15.6M 1 loop /usr/lib/modules loop4 7:4 0 47.9M 1 loop /snap/core18/1945 loop5 7:5 0 50.8M 1 loop /snap/subiquity/2278 loop6 7:6 0 29M 1 loop /snap/snapd/10704 loop7 7:7 0 62.9M 1 loop /snap/lxd/19189 sda 8:0 0 64G 0 disk |-sda1 8:1 0 1G 0 part |-sda2 8:2 0 63G 0 part `-mpathb 253:1 0 64G 0 mpath |-mpathb-part1 253:2 0 1G 0 part /target/boot `-mpathb-part2 253:3 0 63G 0 part `-dm_crypt-0 253:4 0 63G 0 crypt `-ubuntu--vg-ubuntu--lv 253:5 0 31.5G 0 lvm /target sdb 8:16 0 64G 0 disk `-mpatha 253:0 0 64G 0 mpath sdc 8:32 0 64G 0 disk |-sdc1 8:33 0 1G 0 part |-sdc2 8:34 0 63G 0 part `-mpathb 253:1 0 64G 0 mpath |-mpathb-part1 253:2 0 1G 0 part /target/boot `-mpathb-part2 253:3 0 63G 0 part `-dm_crypt-0 253:4 0 63G 0 crypt `-ubuntu--vg-ubuntu--lv 253:5 0 31.5G 0 lvm /target sdd 8:48 0 64G 0 disk `-mpatha 253:0 0 64G 0 mpath sde 8:64 0 64G 0 disk |-sde1 8:65 0 1G 0 part |-sde2 8:66 0 63G 0 part `-mpathb 253:1 0 64G 0 mpath |-mpathb-part1 253:2 0 1G 0 part /target/boot `-mpathb-part2 253:3 0 63G 0 part `-dm_crypt-0 253:4 0 63G 0 crypt `-ubuntu--vg-ubuntu--lv 253:5 0 31.5G 0 lvm /target sdf 8:80 0 64G 0 disk `-mpatha 253:0 0 64G 0 mpath sdg 8:96 0 64G 0 disk |-sdg1 8:97 0 1G 0 part |-sdg2 8:98 0 63G 0 part `-mpathb 253:1 0 64G 0 mpath |-mpathb-part1 253:2 0 1G 0 part /target/boot `-mpathb-part2 253:3 0 63G 0 part `-dm_crypt-0 253:4 0 63G 0 crypt `-ubuntu--vg-ubuntu--lv 253:5 0 31.5G 0 lvm /target sdh 8:112 0 64G 0 disk `-mpatha 253:0 0 64G 0 mpath root@ubuntu-server:/# blkid /dev/loop0: UUID="2021-02-01-17-59-46-00" LABEL="Ubuntu-Server 20.04.2 LTS s390x" TYPE="iso9660" /dev/loop1: TYPE="squashfs" /dev/loop2: TYPE="squashfs" /dev/loop3: TYPE="squashfs" /dev/loop4: TYPE="squashfs" /dev/loop5: TYPE="squashfs" /dev/loop6: TYPE="squashfs" /dev/loop7: TYPE="squashfs" /dev/mapper/mpathb-part2: UUID="3987c78e-f671-4079-ac05-f8b7fe768b55" TYPE="crypto_LUKS" PARTUUID="87303b99-a04d-4c30-b395-f342c79fef70" /dev/mapper/ubuntu--vg-ubuntu--lv: UUID="288689a9-116a-4867-93a2-75a963062c61" TYPE="ext4" /dev/sda1: UUID="1996c31a-e597-4e80-a637-4f2a779508da" TYPE="ext4" PARTUUID="2bc02ff5-a24f-4fc5-a35e-0690a2b4ca61" /dev/sda2: UUID="3987c78e-f671-4079-ac05-f8b7fe768b55" TYPE="crypto_LUKS" PARTUUID="46f12d4e-6396-468d-b8d7-231e3e24e713" /dev/sdc1: UUID="1996c31a-e597-4e80-a637-4f2a779508da" TYPE="ext4" PARTUUID="2bc02ff5-a24f-4fc5-a35e-0690a2b4ca61" /dev/sdc2: UUID="3987c78e-f671-4079-ac05-f8b7fe768b55" TYPE="crypto_LUKS" PARTUUID="46f12d4e-6396-468d-b8d7-231e3e24e713" /dev/mapper/mpathb: PTUUID="0d8b6a8b-cd60-46fd-9ec8-24d5e3541d6f" PTTYPE="gpt" /dev/sde1: UUID="1996c31a-e597-4e80-a637-4f2a779508da" TYPE="ext4" PARTUUID="2bc02ff5-a24f-4fc5-a35e-0690a2b4ca61" /dev/sde2: UUID="3987c78e-f671-4079-ac05-f8b7fe768b55" TYPE="crypto_LUKS" PARTUUID="46f12d4e-6396-468d-b8d7-231e3e24e713" /dev/sdg1: UUID="1996c31a-e597-4e80-a637-4f2a779508da" TYPE="ext4" PARTUUID="2bc02ff5-a24f-4fc5-a35e-0690a2b4ca61" /dev/sdg2: UUID="3987c78e-f671-4079-ac05-f8b7fe768b55" TYPE="crypto_LUKS" PARTUUID="46f12d4e-6396-468d-b8d7-231e3e24e713" /dev/mapper/mpathb-part1: UUID="1996c31a-e597-4e80-a637-4f2a779508da" TYPE="ext4" PARTUUID="ca1fd1ac-f705-4096-954d-7a1b07ab3891" /dev/mapper/dm_crypt-0: UUID="SukiDx-6oBb-g2vY-YoGP-fd6y-fFbD-ZIPf5d" TYPE="LVM2_member" root@ubuntu-server:/# cat /target/etc/fstab # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # # / was on /dev/ubuntu-vg/ubuntu-lv during curtin installation /dev/disk/by-id/dm-uuid-LVM-wZilMCEJKlgdikVkEQdHhMiC8wYpJXVuDn9HuJvMYqYZu5DCbwb7nmGjMthndwJE / ext4 defaults 0 0 # /boot was on /dev/mapper/mpathb-part1 during curtin installation /dev/disk/by-id/dm-uuid-part1-mpath-36005076306ffd6b6000000000000260a /boot ext4 defaults 0 0 /swap.img none swap sw 0 0 root@ubuntu-server:/# cat /target/etc/crypttab dm_crypt-0 UUID=3987c78e-f671-4079-ac05-f8b7fe768b55 none luks