Would a snapper rollback still work with /boot outside the btrfs fiflsystem?

English Install/Boot/Login
1

Hi all, I installed leap 15.3 in virtualbox to test if I could install leap with disk encryption without encrypting /boot.
So I made this partition layout:


UUID=659ad388-a003-4df5-9c6d-9ea70c669c6f  /            btrfs  defaults              0  0
UUID=88ede10f-b45c-4b8b-a785-4d19973ea77c  /boot        ext4   data=ordered          0  2
UUID=7272d6dc-117f-46ac-99e8-56ac847fa08b  swap         swap   defaults              0  0
UUID=659ad388-a003-4df5-9c6d-9ea70c669c6f  /.snapshots  btrfs  subvol=/@/.snapshots  0  0
UUID=659ad388-a003-4df5-9c6d-9ea70c669c6f  /var         btrfs  subvol=/@/var         0  0
UUID=659ad388-a003-4df5-9c6d-9ea70c669c6f  /usr/local   btrfs  subvol=/@/usr/local   0  0
UUID=659ad388-a003-4df5-9c6d-9ea70c669c6f  /tmp         btrfs  subvol=/@/tmp         0  0
UUID=659ad388-a003-4df5-9c6d-9ea70c669c6f  /srv         btrfs  subvol=/@/srv         0  0
UUID=659ad388-a003-4df5-9c6d-9ea70c669c6f  /root        btrfs  subvol=/@/root        0  0
UUID=659ad388-a003-4df5-9c6d-9ea70c669c6f  /opt         btrfs  subvol=/@/opt         0  0
UUID=659ad388-a003-4df5-9c6d-9ea70c669c6f  /home        btrfs  subvol=/@/home        0  0
UUID=493C-733C                             /boot/efi    vfat   utf8                  0  2

Now during the install I did get a warning that this setup might not work, but it worked just fine.
The system booted without problems.

Now naturally with this setup files in /boot will not be part of the snapper snapshots since /boot is not a part of the btrfs filesystem.
So with this setup would a snapper rollback still work?

PS: I wonder if I need snapper at all since I cannot remember when a update of leap broke the system and I been using SuSE/openSUSE since 2001.

2

It depends.

The kernel is in “/boot”, while the kernel modules are in the root file system. If you roll back, will you have a working kernel? As long as there is a kernel in “/boot” with its modules (in “/lib/modules”) still there, you should be able to boot that kernel.

3

I will install leap again tomorrow without a network connection so that after the install there will be a kernel update and see if I can roll back with snapper.

4

And yes, it ‘breaks’ snapper rollback.

I just did an update after install wich contained a kernel update and after booting into this updated system and rebooting again, no snapshot was offered in the grub menu.
That makes sence since the files in /boot contains grub config files and the kernels.

No snapper for me then since I want to encrypt my system but find the long decryption time of grub really annoying!

5

And after some coffee it occurred to me that I could also try to /boot with unencrypted btrfs and snapshots maybe?
I will install leap again to test that!

Learning as I go!

6

Snapper configurations are per-subvolume, snapshots that are created during package installation/removal (and other administrative tasks) are for root subvolume only. Snapper rollback will only revert root subvolume content.

So nothing really changes here.

7

I just found out that’s true.
Super annoying though.

I guess there is no way to achieve what I want?

8

On btrfs level there is no way to create snapshots of multiple subvolumes atomically. On snapper level it could create “related” snapshots close to each other on multiple subvolumes. Someone would need to implement it.

9

Well I’ll just go without snapper snapshots since I can’t recall an update of leap breaking my system.
I do have my backups of critical folders and files on a backup partition and on a external drive.