title: RDS Postgres Free Storage Space is fluctuating from 200GB to 0 hourly
body: <p>As you can see, of the 500GB, we are using ~300GB and thus there is about 200GB that should be free. However, since updating from Postgres 9.4 to 9.5, we are seeing this crazy fluctuation in free storage. It is using the default parameter group as well.</p>
  <p>Is there any way to bring it back to stable? It seems to be causing some queries to fail, too.</p>
  <pre><code>Engine version: 9.5.21
  Instance class: db.t2.large
  CPU: 2
  RAM: 8 GB
  Storage: 500 GiB
  </code></pre>
  <p><a href="https://i.stack.imgur.com/aKzuc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aKzuc.png" alt="enter image description here" /></a></p>
  <p>Some more stats:
  <a href="https://i.stack.imgur.com/3u52f.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3u52f.png" alt="enter image description here" /></a></p>