[hadoop@master ~]$ start-dfs.shIncorrect configuration: namenode address dfs.namenode.servicerpc-address or dfs.namenode.rpc-address is not configured.Starting namenodes on []Error: Cannot find configuration directory: /etc/hadoopError: Cannot find configuration directory: /etc/hadoopStarting secondary namenodes [0.0.0.0]Error: Cannot find configuration directory: /etc/hadoop

[hadoop@master ~]$  vi /opt/software/hadoop-2.7.7/etc/hadoop/hadoop-env.sh

   export HADOOP_CONF_DIR=/opt/software/hadoop-2.7.7/etc/hadoop

[hadoop@master ~]$ source /opt/software/hadoop-2.7.7/etc/hadoop/hadoop-env.sh