Re: rollback to a snapshot

[Eldon <btrfs@eldondev.com>]

On Tue, Jun 06, 2023 at 08:58:03PM +0000, Bernd Lentes wrote:
> Hi guys,
> 
> thanks for your help.
> 
> I have an Ubuntu box which I wanted to upgrade. Fortunately I made a snapshot before.
> The upgrade ran only partially and now I want to go back to my snapshot.
> I booted the system now with a recuse cd.
> This is my setup:
> 
> root@Microknoppix:/home/knoppix# mount|grep btrfs
> /dev/mapper/ubuntu--vg-ubuntu--lv on /mnt/btrfs type btrfs (rw,relatime,space_cache,subvolid=5,subvol=/)
> 
> root@Microknoppix:/home/knoppix# btrfs sub list /mnt/btrfs
> ID 430 gen 1215864 top level 5 path .snapshots
> ID 434 gen 1213568 top level 430 path .snapshots/06-06-2023--15:16_PRE_UPGRADE
> ID 435 gen 1216086 top level 430 path .snapshots/06-06-2023
> I want to go back to ID 434 or 435.

Hi Bernd,
I would generally agree that changing the default subvolume is the best
strategy to get the desired result. I would create a new writable
subvolume from the snapshot you want to use, in a reasonable place to
put it. I use my own idiosyncratic paths, but you can use whatever you
want. I would use a destination outside of the .snapshots directory,
maybe something like .live .
Then, do the btrfs subvolume set-default to that subvolume.

That's how I usually do my rollbacks, hope it helps with your situation.

Cheers,
Eldon