title: How can I update data with RRDtool?
body: <p>I am using RRDtool for storing data for displaying graphs. I update the RRD by  RRDs::update and this fails when trying to rewrite the information, means update data for a time in the past (e.g. someone moved the system timer back). The error I get is: </p>
  
  <pre><code>ERROR: Cannot update /opt/dashboard/rrd/Disk/192.168.120.168_disk_1.rrd with 
  '1228032301:24:24' illegal attempt to update using time 1228032301 when last 
  update time is 1228050001 (minimum one second step)
  </code></pre>
  
  <p>I want to always allow the rewrite, how can I do this?</p>