Grub

ip l add link enp24s0f0np0 name dev3633 type vlan id 3633
ip l set dev dev3633 up
dhclient dev3633 
 
apt update
apt install mdadm
mdadm --assemble --scan
 
mount /dev/mapper/system-root /mnt/
 
mount --bind /dev/ /mnt/dev
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
 
chroot /mnt
mount -a
 
#modprobe nvram
 
update-grub

Fix "failed to connect to lvmetad"
https://askubuntu.com/questions/745218/ubuntu-wont-boot-because-of-lvmetad

vi /etc/lvm/lvm.conf
use_lvmetad = 0

Links
https://wiki.gentoo.org/wiki/GRUB2/Chainloading
https://wiki.ubuntuusers.de/GRUB/GRUB-Shell/
https://wiki.archlinux.org/index.php/GRUB/Tips_and_tricks#Alternative_installation_methods