Hadoop中dataNode启动不了

1. 查看log日志

1）打开网址：http://localhost:50070

2）选择Utilities->logs

3)选择hadoop-hadoop-datanode.log

查看其中的错误

2.我的错误是

**********************************************************/
2016-10-19 11:13:45,972 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: registered UNIX signal handlers for [TERM, HUP, INT]
2016-10-19 11:13:48,056 WARN org.apache.hadoop.util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2016-10-19 11:13:48,801 FATAL org.apache.hadoop.hdfs.server.datanode.DataNode: Exception in secureMain
java.net.UnknownHostException: Zewen: Zewen
at java.net.InetAddress.getLocalHost(InetAddress.java:1496)
at org.apache.hadoop.security.SecurityUtil.getLocalHostName(SecurityUtil.java:187)
at org.apache.hadoop.security.SecurityUtil.login(SecurityUtil.java:207)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:2153)
at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:2202)
at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:2378)
at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:2402)
Caused by: java.net.UnknownHostException: Zewen
at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:922)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1316)
at java.net.InetAddress.getLocalHost(InetAddress.java:1492)
... 6 more
2016-10-19 11:13:48,825 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 1
2016-10-19 11:13:48,844 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down DataNode at java.net.UnknownHostException: Zewen: Zewen
************************************************************/
2016-10-19 11:29:32,211 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG:

3.解决方案

其中查找网络的语句是：

      hostname 语句

解决：通过查找/etc/hostname 找到hostname；比如：Zewen。

然后找到/etc/hosts ，

gedit hosts

然后添加：127.0.1.1 Zewen

重启即可