title: Can't connect to local mongoDB install
body: <p>After downloading, extracting, creating the <code>data/db</code> folder and cd-ing into where I extracted mongoDB, I tried running this command, as directed by the official mongoDB install instructions: <code>.bin/mongo/</code> but I keep getting this error: </p>
  
  <p><code>Error: couldn't connect to server 127.0.0.1:27017 src/mongo/shell/mongo.js:91</code></p>
  
  <p>I can't find a concise explanation on the internet, though it seems to be a common problem, and the mongoDB docs aren't clear either. Can anyone help me out?</p>