yes do backup ,
if you backup all ( / and /home ) ,
you restore by grsync or timeshift
boot on USB iso manjaro
1 backup each partition
2 launch gparted format GPT and create /boot/efi ( 33 to 100Mo fat32 with flag boot & esp ),
/ and /home
3 restore back for / and /home
4 you will go in chroot for
a - update new UUID
( lsblk -fs & /etc/fstab )
redo a 2nd chroot for EFI
b - restore GRUB for EFI
for check before format GPT and restore backup that all efi is ok
open a terminal and check
inxi -Fza
sudo parted -l
sudo efibootmgr -v
test -d /sys/firmware/efi && echo efi || echo legacybios
after restore backup
get all UUID
sudo fsblk -fs
*update /etc/fstab UUID a /boot/efi by chroot
add line for /boot/efi and update all UUID
sudo manjaro-chroot -a
nano /etc/fstab
exit ( end chroot )
as example , change UUID !!!
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a device; this may
# be used with UUID= as a more robust way to name devices that works even if
# disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
UUID=AAAA-BBBB /boot/efi vfat defaults,noatime 0 2
*restore grub en /boot/efi ( 2nd chroot to get /boot/efi UUID with /etc/fstab )
sudo manjaro-chroot -a
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=manjaro --recheck --verbose
update-grub
efibootmgr -v
exit ( end chroot )
then you can reboot , press F2 or F8 or F12 to go in bios ans select UEFI manjaro