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No joy, but that is as expected. The instructions at http://hadoop.apache.org/docs/r2.4.1/hadoop-project-dist/hadoop-hdfs/HdfsPermissionsGuide.html#Configuration_Parameters let me know I need to make sure there is a dfs.permissions.superusergroup KVP created for hdfs-site.xml. This parameter can be found in Ambari at Services > HDFS > Configs > Advanced > dfs.permissions.superusergroup. For my Hortonworks Sandbox this value is set to hdfs. This also aligns with the fact that unless you do a −chgrp, your newly created items have the group set to hdfs on this little pseudo-cluster. Contrary to what you would expect (i.e. the group becomes the value for this setting), I did find out later that even with a different superusergroup identified, the owning group stayed as hdfs.
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