I just tried it. It is just a POST to the /api/v10/users endpoint. curl -u uname:passw -H "Content-Type: application/json" -X POST -d '{ "items" : [ { "name" : "matt", "password" : "test" } ] }' http://cm_host:7180/api/v15/users ... View more

I think 'No storage dirs specified.' is referencing your dfs.data.dirs. Also, it is possible that the env vars like HADOOP_CONF_DIR are not set correctly for the session you are running that command in. As for the JN error, it seems that it is trying to format the NN but data already exists in the JN edits directory. Was NN HA working prior to Kerberos being enabled? If you are cool with formatting the NN then you are likely fine with manually removing the data in the JN edits directory. I would back it up in case and then remove it and see if the NN can come online. Also, did you have NN HA enabled and then disabled it? This is the only time I have seen data already in place in the JN edits directory. Rolling back NN HA in CM does not clear out this data. ... View more

It is related to an JMX counter within the Datanode process.  I am not sure what it is counting but it something within it is throwing an NPE.  This is likely coming after the write stream has process all data but since it hits this exception it throws and exits.  It should be safe to ignore this error.   getDatanodeNetworkCounts  A related JIRA although it doesn't seem to be part of CDH yet.   https://issues.apache.org/jira/browse/HDFS-7331 ... View more