RedHat6.4 Hadoop格式化HDFS出现java.net.UnknownHostException

[doing820000]

我在hadoop2.2.0中格式化namenode出现如下异常
hdfs namenode -format
14/12/16 19:35:15 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = java.net.UnknownHostException: LiaoZhanLin: LiaoZhanLin
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 2.2.0

这是为什么？还有，我这样做了以后，启动hadoop却始终启动不了datanode,其他几项可以启动，这又是为什么？
我的hdfs-site.xml内容为
configuration>
<property>
<name>dfs.namenode.name.dir</name>
<value>file:/opt/software/hadoop2.0/data/dfs/name/namenode</value>
<final>true</final>
</property>

<property>
<name>dfs.datanode.data.dir</name>
<value>file:/opt/software/hadoop2.0/data/</value>
<final>true</final>
</property>

<property>
<name>dfs.replication</name>
<value>1</value>
</property>

<property>
<name>dfs.permissions</name>
<value>false</value>
</property>

</configuration>
请大家帮我解决，谢谢！