https://community.cloudera.com/t5/Support-Questions/namenode-is-not-formatted/m-p/183899#M146057 <P>Our server had to be restarted so we are trying to start all of the process :</P><P>I keep getting this error. Why is that? How do I fix this? It is urgent as Namenode was on the master node and now the cluster is not working. Please help</P><TABLE><TBODY><TR><TD><PRE>Failed to start namenode. java.io.IOException: NameNode is not formatted. at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:212) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFSImage(FSNamesystem.java:1063) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFromDisk(FSNamesystem.java:767) at org.apache.hadoop.hdfs.server.namenode.NameNode.loadNamesystem(NameNode.java:609) at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:670) at org.apache.hadoop.hdfs.server.namenode.NameNode.&lt;init&gt;(NameNode.java:838) at org.apache.hadoop.hdfs.server.namenode.NameNode.&lt;init&gt;(NameNode.java:817) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1538) at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1606)</PRE></TD></TR></TBODY></TABLE> Sat, 01 Apr 2017 13:25:59 GMT simran_k 2017-04-01T13:25:59Z