[opensuse] What fills root if not snapshots

Hi all, This Asus laptop (with TW and KDE) was not used for ten days. Yesterday evening I switched it on and saw I have >800 updates. I tried tio install them with zypper dup. I failed, because root got full. This was with 4.18.0 kernel. I managed to boot into 4.17.14 kernel (got some complaints, but none showstopper) and manually remove all downloaded rpm packages from /var/cache/zypp/packages with mc. Dolphin did not start in superuser mode. All these deleted and having only the 0 and 1 snapshots, I have less than 600 M in root from 40 G. And I have no idea where is the rest of the space? Can I get any help? Albert