title: Google Cloud Storage for incremental backup
body: <p>I have a linux machine with some website (normally in /usr/local/apache/htdocs). I would like to create a incremental backup (minimum 7 days) for all data in a my bucket.
  I have created a bucket as Coldline and I have used rsync for syncing my local folder to the bucket.
  If I use a rsync tomorrow, the new files is automatically uploaded to the bucket...but how can I delete (after minimum 7 days) the old files?</p>
  
  <p>I use this for rsync: gsutil -m rsync -r /usr/local/apache/htdocs gs://my_bucket</p>
  
  <p>(without the remove tag, because i would keep the deleted files for some days...)</p>
  
  <p>Thank you!</p>