In Fedatated HDFS, same DataNodes can work with multiple NameNode.
Where as in your setup, complete cluster itself is different.
I would suggest you to take a look at HDFS-2471, Suresh has explained very neet and breifly here.
From: Sesha Kumar [[EMAIL PROTECTED]]
Sent: Monday, November 28, 2011 9:05 AM
To: [EMAIL PROTECTED]
Subject: Clarification on federated HDFS
Is Federated HDFS same as having a set of individual Hadoop Clusters, each managing its own namespace and knowing nothing about the existence of other clusters (but having separate set of data nodes instead of a common pool)? Assuming we have something similar to ViewFS which provides a single global namespace combining the namespaces of each namenode and it also provides some facility to add new namenodes to the setup.
What are the differences between Federated HDFS and the above given setup?