It is in by-label:Does this device appear in the /dev/disk/by-label/ directory? If not, then udev has no knowledge of a thing with LABEL "root". Your system will still boot because grub knows which device to pass to the kernel regardless of what is in fstab.
# ls -l /dev/disk/by-label/
total 0
lrwxrwxrwx 1 root root 15 Nov 17 10:58 ESPANDY ->
../../nvme0n1p1
lrwxrwxrwx 1 root root 15 Nov 17 10:58 disk2 -> ../../nvme1n1p1
lrwxrwxrwx 1 root root 15 Nov 17 10:58 root -> ../../nvme0n1p2
In this case of missing LABEL it can be proven that old metadata is the cause by running: # wipefs -na /dev/nvme0n1p2 This will not wipe anything, it will only list what it can find. You can later wipe individual signatures (will not damage the ext4 that is on there).
# wipefs -na /dev/nvme0n1p2
wipefs: error: /dev/nvme0n1p2: probing initialization failed:
Device or resource busy
Do I need to run it from a rescue disk?
The disk is new, but I did make a mistake during the installation that caused me to start over with a fresh mkfs (but the existing partition table).
ITYhis is my best guess based on having seen before when filesystem
LABELs are not detcted by udev. If this isn't what's happening for you then I think I am out of ideas. At least verifying that the thing exists in /dev/disk/by-label will show that udev finds the LABEL on that drive (or not).
Thanks a lot for your help,
Jesper
-- Jesper Dybdal https://www.dybdal.dk