Package: grub-common Version: 2.04-20 Severity: important Tags: upstream the core issue is that grub-probe is not reporting cryptodisk abstraction when the block device below the lvm is luks encrypted.
/usr/share/grub/grub-mkconfig_lib relies on this output to decide whether to create the background cache on the /boot partition. because cryptodisk is not returned as an abstraction, the cache is never created and cannot be displayed at boot time. this is the output of grub-probe: # grub-probe -t abstraction /usr/share/images/desktop-base/desktop-grub.png lvm however, the file is definitely on an encrypted lvm volume: # stat --printf="%m\n" /usr/share/images/desktop-base/desktop-grub.png / # lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS nvme0n1 259:0 0 476.9G 0 disk ... └─nvme0n1p3 259:3 0 476.7G 0 part └─nvme0n1p3_crypt 253:0 0 476.7G 0 crypt └─fnord--vg-root 253:1 0 476.7G 0 lvm / # mount -vf / mount: /dev/mapper/fnord--vg-root mounted on /. # pvdisplay PV Name /dev/mapper/nvme0n1p3_crypt VG Name fnord-vg ... # cryptsetup status nvme0n1p3_crypt /dev/mapper/nvme0n1p3_crypt is active and in use. type: LUKS2 device: /dev/nvme0n1p3 ...