title: best practice to backup config files Jenkins
body: <p>I am using Jenkins on remote Debian 7.8 . I want to update Debian 7.8 to 8.7. I tried to update and it went fine however Jenkins was broken and could not start the service. I tried everything but could find any solution. Finally I used purged command and it deleted previous configurations and builds.</p>
  
  <p>Now I restore the server and want to update again but I want a complete Jenkins backup of config  and builds so restore it from last running instance.  </p>
  
  <p>What's the best practice to backup the configs as simple as possible (with less effort and problems) and configure and then merge the backuped files.</p>
  
  <p>Which data / config files I have to backup?</p>