title: How to delete prometheus log files? Cannot start prometheus by using systemd
body: <p>I start up prometheus failed.error log info:
    <a href="https://i.stack.imgur.com/qaubX.png" rel="nofollow noreferrer">enter image description here</a></p>
  
  <p>I check prometheus log:</p>
  
  <p><a href="https://i.stack.imgur.com/TCatz.png" rel="nofollow noreferrer">enter image description here</a>
  Have question:</p>
  
  <p>1: How to delete these log files?
  2：how to Loop write to a log files?</p>
  
  <p>Thanks!</p>