在阿里云服务器上安装hadoop，启动后没有namenode进程，查看log文件发现报如下错误：java.net.BindException: Problem binding to 

[smice:9000] java.net.BindException: Cannot assign requested address; For more details see: http://wiki.apache.org/hadoop/BindException

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

查看hadoop官方文档，http://wiki.apache.org/hadoop/BindException，只提到了了端口被占用的情况。

仔细排查了一下是hosts的ip与网卡ip一致。我把hostname用外网ip映射hosts，改成内网ip即可。