https://community.cloudera.com/t5/Support-Questions/namenode-is-not-formatted/m-p/183903#M146061 <P><A rel="user" href="https://community.cloudera.com/users/10310/rchoksi.html" nodeid="10310">@Romil Choksi</A></P><P>Also,</P><TABLE><TBODY><TR><TD><PRE>Maximum size of an xattr: 16384 </PRE> </TD></TR><TR> <TD>Apr 1, 11:45:18.670 AM</TD><TD>INFO</TD><TD>org.apache.hadoop.hdfs.server.common.Storage</TD> <TD><PRE>Lock on /dfs/nn/in_use.lock acquired by nodename 9392@warehouse.swtched.com </PRE> </TD></TR><TR> <TD>Apr 1, 11:45:18.672 AM</TD><TD>WARN</TD><TD>org.apache.hadoop.hdfs.server.namenode.FSNamesystem</TD> <TD><PRE>Encountered exception loading fsimage 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><TR> <TD>Apr 1, 11:45:18.684 AM</TD><TD>INFO</TD><TD>org.mortbay.log</TD> <TD><PRE>Stopped HttpServer2$SelectChannelConnectorWithSafeStartup@warehouse.swtched.com:50070</PRE></TD></TR></TBODY></TABLE> Sat, 01 Apr 2017 13:53:51 GMT simran_k 2017-04-01T13:53:51Z