How do I install single countries after initial install of nominatim?

Yesterday I succeed to install Nominatim as our API for using reverse Geolocation but I only imported one country initially. I followed the instructions in https://wiki.openstreetmap.org/wiki/Nominatim/Installation and used ./utils/setup.php --osm-file --all [--osm2pgsql-cache 18000] 2>&1 | tee setup.log

Today I´m about to add more countries and I use the same commands but I get database already exist.

How can I add single countries now after install?

I found a suggestion at https://help.openstreetmap.org/questions/15505/import-more-osm-files-in-to-nominatim and used ./utils/update.php --import-file --osm2pgsql-cache 12000 and I got no errors. After that I made ./update.php --index also with no errors and it was very fast 30 seconds, not like my initial install that took me 10 hours so I suppose something doesn't add up here. Also when trying to search for addresses from my last import thru the local web interface I can't find any.

Any ideas?