Configure a federation with a cluster upgrade
Hortonworks Data Platform versions starting with 3.0.0 support HDFS federations. You can configure the federation as you upgrade your cluster.
Use the
hdfs start namenode command during the upgrade process as
specified.
hdfs start namenode --config $HADOOP_CONF_DIR -upgrade -clusterId <cluster_ID>
If you do not specify the Cluster ID, then a unique ID is auto-generated.