It's a personal relay only for backing up your posts. It's not accessable from the Internet by other people.
It'll only use a few hundred megabytes tops.
Discussion
Ah ok, I didn't know that.
So my notes are saved and everyone else can see them, but the relay itself cannot be used by others.
It could be in theory. People need the address for your relay, it must be reachable from outside (either via Tor or forwarded port) and they need to actively add your relay in their client of choice. Then they will also be querying your relay for posts and pushing their notes to your relay.
ok, thank you!
I'll give it a try! :)