Hello, My case was indeed a disk switch from USB to internal.
I probably had invoked directly grub-install (dunno if it'd make sense to warn about the mismatch with debconf there?), now I know I should rather use dpkg-reconfigure instead. # debconf-get-selections |grep 'grub-pc/install_devices' grub-pc grub-pc/install_devices_disks_changed multiselect /dev/disk/by-id/usb-KINGSTON_SA400S37240G_0000AB12362D-0:0 grub-pc grub-pc/install_devices_failed_upgrade boolean true grub-pc grub-pc/install_devices_failed boolean false grub-pc grub-pc/install_devices_empty boolean false grub-pc grub-pc/install_devices multiselect /dev/disk/by-id/usb-KINGSTON_SA400S37240G_0000AB12362D-0:0 # ls /dev/disk/by-id/usb-KINGSTON_SA400S37240G_0000AB12362D-0:0 ls: impossible d'accéder à '/dev/disk/by-id/usb-KINGSTON_SA400S37240G_0000AB12362D-0:0': Aucun fichier ou dossier de ce type # ls /dev/disk/by-id/ata-KINGSTON_SA400S37240G_50026B7683315755 /dev/disk/by-id/ata-KINGSTON_SA400S37240G_50026B7683315755@ # dpkg-reconfigure grub-pc # debconf-get-selections |grep 'grub-pc/install_devices' grub-pc grub-pc/install_devices_failed boolean false grub-pc grub-pc/install_devices multiselect /dev/disk/by-id/ata-KINGSTON_SA400S37240G_50026B7683315755 grub-pc grub-pc/install_devices_disks_changed multiselect /dev/disk/by-id/ata-KINGSTON_SA400S37240G_50026B7683315755 grub-pc grub-pc/install_devices_empty boolean false grub-pc grub-pc/install_devices_failed_upgrade boolean true Thanks for the explanations!
