Solved Map seed

Hei guys, how I can change my map seed?
I play on standart map, but in server, where I played was better (http://map.playrust.io/?81.0.217.181:27732)
Its possible?

 

Thanks
[DOUBLEPOST=1431885507][/DOUBLEPOST]I have next questio to create a seed.
How I can do enlarge map, from 4000 to 8000?
+server.worldsize 8000 will cash my server and dont run that.

 

if it crashs it means you server can't handle it