title: MongoDB downgrade from 2.1 to 2.0
body: <p>I made some tests with MongoDB 2.1 (unstable debian package). I want to test the code with 2.0 stable to see the speed difference. </p>
  
  <p>Can I simply uninstall  mongoDB 2.1 and reinstall 2.0 without caring about the data ?</p>
  
  <p>Thanks</p>