HA configuration is backward compatible and works with your existing single NameNode configuration. The following instructions describe how to set up NameName HA on a manually-installed cluster. If you installed with Ambari and manage HDP on Ambari 1.4.1 or later, instead of these instructions use the Ambari documentation for the NameNode HA wizard.
![[Note]](../common/images/admon/note.png) | Note |
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HA cannot accept HDFS cluster names that include an underscore (_). |
To deploy a NameNode HA cluster:
