I can say that the Snapper (Btrfs Assistant) - Grub-Btrfs (and inotify-tools) duo is not working as it is supposed to. So what is it supposed to be?
- Snapper automatically takes snapshots as configured by the user. Sometimes the user also takes snapshots manually through Snapper. Also Snapper automatically deletes old snapshots.
- Grub-Btrfs adds or removes these three processes as a list of bootable snapshots in the bootloader.
- To rollback system to one of the old snapshots, the user choose a read-only snapshot from the bootloader.
- Makes the writable version of the read-only snapshot the default via Snapper.
- The user reboots their system, still sees Grub-Btrfs’s list of bootable snapshots in the bootloader, making sure everything is where it should be, confirming that when the system starts it is in the exact snapshot they want to rollback to.
That’s what is experienced on openSUSE and that’s what the Snapper - Grub-Btrfs duo should promise, that’s what is supposed to happen. But in reality things break at step 5 and Grub-Btrfs no longer adds bootable snapshots to the bootloader.
I came across a video that claims that the Snapper - Grub-Btrfs duo works 100%, but as you can see at the end of this video, breaks down. Watch second video carefully, the last time he restarted the system there should have been 3 (or maybe 2) entries in the bootloader list but there are not. Before that he ran grub2-mkconfig, but even then not all snapshots were added to the bootloader. On openSUSE you don’t need to run grub2-mkconfig command every time.