I've used Syncthing in the past to keep different volumes in "sync" in a distributed system. The API was simple enough to plug into an orchestration framework,

I've used Syncthing in the past to keep different volumes in "sync" in a distributed system. The API was simple enough to plug into an orchestration framework, and for quick/dirty projects it's phenomenal. Right now I'm actually using it for a very small minecraft server on Fly.io. The game server runs on a "bigger" instance, and there's a web server running on a much smaller (and therefore "free") instance, for displaying the game map and similar things. Syncthing copies the generated squaremap tiles to the webserver, so when the game server is down, the map is still available