Missing command detecting ZFS-ID

[Advantaged]

Thanks first for very good explanation, that's seldom by people explaining ZFS.
Good Job, well done!
With your instruction was I able to install Kubuntu 18.04 on ZFS in VB and feel confident to install on production machine, thanks again.

Only one thing for new-bee like me is important: detect "/dev/disk/by-id/" used by ZFS after "apt install -y zfsutils" with following command:

ls -lh /dev/disk/by-id/

By the way! can you make a recommandation for further "Snapshots"?
E.g.:
sudo zfs snapshot tony001/ROOT/kubuntu-1@post-reboot-updates-20190928

How can I choose a snapshot by booting?

Is there a GUI-Tool for managing snapshot and more under Linux?

Thanks again for great job and patience with me.