title: Speed rates on Grafana, influxdb
body: <p>Details:</p>
  
  <ul>
  <li>Grafana version: 2.5.0</li>
  <li>Datasource: influxdb</li>
  <li>OS: ubuntu server 14.04</li>
  </ul>
  
  <p>I was trying to get the current speed rate in megabit/s from a server interface but I cannot figure out how to transform "if_octets" in Megabit/s using Grafana. Or better I don't know what query to use.</p>
  
  <p>I used this query but I have no output</p>
  
  <pre><code>select derivative(mean(value), 1s) from "interface_rx" where "istance" ='em1' and "type" = 'if_octects' and time &gt; now() - 4h group by time(1m) 
  </code></pre>