Hi all,

I have installed SuSE 12 where root and boot are different file systems. The root is BTRFS and boot is ext4. This installation has subvolumes for root. I have question related to below subvolumes
ID 258 gen 244451 top level 257 path boot/grub2/i386-pc
ID 259 gen 235020 top level 257 path boot/grub2/x86_64-efi

These subvolumes get mounted on same directories. The fstab entries are:
UUID=e13a6b2a-29f4-4eba-87db-d38b00baa6cd / btrfs defaults 0 0
UUID=bc06c806-ee5c-44f7-99f9-bb7c84418ab8 /boot ext4 acl,user_xattr 1 2
UUID=e13a6b2a-29f4-4eba-87db-d38b00baa6cd /boot/grub2/i386-pc btrfs subvol=@/boot/grub2/i386-pc 0 0
UUID=e13a6b2a-29f4-4eba-87db-d38b00baa6cd /boot/grub2/x86_64-efi btrfs subvol=@/boot/grub2/x86_64-efi 0 0

When the /boot/grub2/i386-pc gets mounted on /boot/grub2/i386-pc, the contents of /boot/grub2/i386-pc gets hidden. Since the original contents of /boot/grub2/i386-pc are required for the OS to boot; how does the OS handle this situation?
How should a backup software handle this situation because since the contents are hidden due to the subvolume, it will not backup the original contents and restore will not work as expected?