snapshotting is not recursive, nofiles in the nested appear in the snapshot.
a subvolume or snapshot is a barrier, so nested subvolume layout can be used to achieve fine grained control on what is being rolled back.
there are mount options like noatime, ro (read only), rw (read write), and you can mount a rw snapshot as read only.
Install grub-btrfs package
sudo pacman -S grub-btrfsedit the config file
sudo -E systemctl edit grub-btrfsdif you use timeshift, you should change the command line accordingly.
sudo grub-mkconfig -o /boot/grub/grub.cfg
sudo systemctl enable grub-btrfsd --nowsudo btrfs subvolume snapshot -r / /@snap
# -r for readonly
sudo btrfs subvolume delete /
sudo btrfs subvolume snapshot /@snap /There is a package in aur called timeshift-autosnap, which will automatically create snapshots upon system update.