1. Configuring ACLs on HDFS

Only one property needs to be specified in the hdfs-site.xml file in order to enable ACLs on HDFS:

dfs.namenode.acls.enabled
Set this property to "true" to enable support for ACLs. ACLs are disabled by default. When ACLs are disabled, the NameNode rejects all attempts to set an ACL.
Example:
```
<property>
 <name>dfs.namenode.acls.enabled</name>
 <value>true</value>
</property>
```