4，org.apache.hadoop.security.AccessControlException: Permission denied: user=root, access=WRITE, in

org.apache.hadoop.security.AccessControlException:Permission denied: user=root, access=WRITE,inode="/user":hdfs:supergroup:drwxr-xr-x  问题解决：

a，修改hdfs-site.xml：

  <property>

         <name>dfs.permissions</name>

         <value>false</value>

  </property>

b，如果a步骤不行，执行[root@namenode1 lixun] > su hdfs