This error message usually indicates that the Java class org.apache.hadoop.hdfs.server.namenode.NameNode could not be found or loaded. This class is a part of the Apache Hadoop project and is used to start the NameNode daemon, which is responsible for managing the HDFS file system namespace.
There are a few possible reasons why you might see this error:
The Hadoop JAR files are not in the classpath. Make sure that all the required Hadoop JAR files are present in the classpath when you try to start the NameNode daemon.
There is a problem with the Hadoop installation. Make sure that Hadoop is properly installed and configured on your system.
There is a conflict with another version of Hadoop. If you have multiple versions of Hadoop installed on your system, make sure that you are using the correct version when starting the NameNode daemon.
There is a problem with the Java installation. Make sure that you have a compatible version of Java installed on your system and that it is properly configured.
If none of these suggestions help, it may be helpful to examine the Hadoop log files for more information about the cause of the error. These log files are typically located in the $HADOOP_HOME/logs directory