title: File permissions on HDFS
body: <p>I find a lot of tutorials that guide users on how to "create users/groups" on HDFS. I wonder what an "owner" or "group" means in the context of HDFS.</p>
  
  <p>Moreover, who is the owner or group user of a file when it is on HDFS? <a href="http://www.informit.com/articles/article.aspx?p=2755708&amp;seqNum=3" rel="nofollow noreferrer">Some</a> sources say it is <code>hdfs</code> itself, whereas <a href="https://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-hdfs/HdfsPermissionsGuide.html#The_Super-User" rel="nofollow noreferrer">some</a> say it is the user of the client process. </p>
  
  <p>I want to know so that there is a definitive way to understand and fix <code>permission denied</code> errors.</p>