Restore GRUB in UEFI + LVM + LUKS setup (Manjaro)

restore_grub_manjaro.txt

Setup: UEFI, LVM + LUKS encrypted drive
Bootloader: Grub
Links:
 - https://wiki.manjaro.org/index.php/Restore_the_GRUB_Bootloader
 - 
 
Restore GRUB (boot into live env):

# get the encrypted partition (crypto_LUKS)
lsblk -f
cryptsetup open --type luks /dev/sda2 lvm
mount /dev/mapper/cryptVG-root /mnt
mount /dev/sda1 /mnt/boot  # boot partition

mount -t proc proc /mnt/proc
mount -t sysfs sys /mnt/sys
mount -o bind /dev /mnt/dev
mount -t devpts pts /mnt/dev/pts/
modprobe efivarfs

chroot /mnt
# I get the "EFI variables are not supported on this system." so do this:
mount -t efivarfs efivarfs /sys/firmware/efi/efivars

pacman -S mtools os-prober  # probably not needed

# set use_lvmetad = 0  in /etc/lvm/lvm.conf

sudo grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=manjaro_grub --recheck
update-grub

# set use_lvmetad to previous value  in /etc/lvm/lvm.conf

REBOOT and should work

Note: If initial ramdisk env needs to be updated and boot is unsuccessful do this:
- chroot like here but don't mount the boot partition
- make sure use_lvmetad is set correctly
mkinitcpio -p linux41