Hello Everybody,
i am desperate, but i still try to make my Own OSM Tile Server.
For Those who dont know what i already tried:
What i am Now Trying, import different data with --prefix.
Idea: https://trac.openstreetmap.org/ticket/4796 (Answer)
I imported Northern Ireland. OK
I now imported luxembourg (Prefix luxembourg) and belgium (prefix Belgium)
Tablenames: beligum_nodes, belgium_ways, … and so on.
Now i deleted the Tiles ( in the cache) and restarted the Render job.
But it just show me the Northern Ireland… The Area of belgium / luxembourg is not available! 
There are red Tiles…
How can i say to the Render Job: Hey bro… look also for belgium_ xxxx and not only planet_xxxxx
I am not interested anymore how i import it. I just want a tile server i dont know how!
I hope someone can help me.
Best regards
errox