Exception in thread "main" java.io.IOException: This is not a DFS

[hadoop@Master ~]$ start-all.sh
namenode running as process 2985. Stop it first.
192.168.0.237: starting datanode, logging to /usr/hadoop/libexec/../logs/hadoop-hadoop-datanode-Slave1.Hadoop.out
192.168.0.239: starting datanode, logging to /usr/hadoop/libexec/../logs/hadoop-hadoop-datanode-Slave2.Hadoop.out
192.168.0.234: starting datanode, logging to /usr/hadoop/libexec/../logs/hadoop-hadoop-datanode-Slave3.Hadoop.out
192.168.0.235: starting secondarynamenode, logging to /usr/hadoop/libexec/../logs/hadoop-hadoop-secondarynamenode-Master.Hadoop.out
192.168.0.235: Exception in thread "main" java.io.IOException: This is not a DFS
192.168.0.235:  at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.getInfoServer(SecondaryNameNode.java:386)
192.168.0.235:  at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.initialize(SecondaryNameNode.java:169)
192.168.0.235:  at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.<init>(SecondaryNameNode.java:129)
192.168.0.235:  at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.main(SecondaryNameNode.java:567)
jobtracker running as process 2504. Stop it first.
192.168.0.239: starting tasktracker, logging to /usr/hadoop/libexec/../logs/hadoop-hadoop-tasktracker-Slave2.Hadoop.out
192.168.0.234: starting tasktracker, logging to /usr/hadoop/libexec/../logs/hadoop-hadoop-tasktracker-Slave3.Hadoop.out

192.168.0.237: starting tasktracker, logging to /usr/hadoop/libexec/../logs/hadoop-hadoop-tasktracker-Slave1.Had

发现在配置core-site.xml文件中把hdfs://写错为http://；