Can you run 2 minecraft servers at the same time on a mac How do you?

Answer 1

I doubt it's possible to run 2 minecraft servers from the same IP address, given that's the unique identifier for a server (or a domain name which is really just an IP mask). Assuming you did get 2 IP addresses assigned to your computer (which probably requires some serious tinkering with your OS, regardless of which you use), it should be a relatively simple matter of running 2 instances of the minecraft server application and having each one latch on to its own IP address.

That said, it really seems like a bad idea. Unless you have something that's blurring the line between basic terminals (the kind of computer owned by ordinary people) and supercomputers (the kind of computer that grinds through massive calculations and is generally only owned by IT companies, universities and governments), your computer probably can't even handle having 2 server instances running at capacity. Minecraft, despite all the polishing it's gotten since Release Day, is still a huge resource hog, and server applications are always much harder on resources than the client version of the game (having to keep track of many different clients' data at once and make them interact properly is a far more complex matter than when there's only one player). I could see having enough computing power to handle 2 servers if there was 1, maybe 2 players on each, but if you're actually using them practically, it's not very likely.

There's also the issue of data clashing. I'm not sure how the server side of Minecraft is set up, but if its anything like the client version, a lot of the settings will be stored in a hardcoded location. Unless you have 2 unique installs, both servers will be running on the same version of minecraft (including all mods, etc). It's possible it could even try to run 2 separate servers using the same map files. If so, modifications made to the map on one server would effect the other. Not a good plan.

So in short, while it might be theoretically possible, the result would likely be horrifying.