How can I tell where mongoDB is storing data? (its not in the default /data/db!)

mongod defaults the database location to /data/db/.

If you run ps -xa | grep mongod and you don’t see a --dbpath which explicitly tells mongod to look at that parameter for the db location and you don’t have a dbpath in your mongodb.conf, then the default location will be: /data/db/ and you should look there.