Hi!
Yes, the data will persist.
If you do not specify a persistence_path, as describre here, by default, it will store your data in ~/.local/share/weaviate
If you have issues running the embedded client, because there is another process binding to that port, you will need to kill the process.
So:
ps aux | grep weaviate
then kill the ID of the running process.
Let me know if that helps!