我是完全分布式，一台M，两台S。
下面是日志：
2016-04-27 17:47:19,473 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down DataNode at slave1/192.168.0.201
************************************************************/
2016-04-27 17:50:37,877 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting DataNode
STARTUP_MSG: host = slave1/192.168.0.201
STARTUP_MSG: args = []
STARTUP_MSG: version = 0.20.2
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20 -r 911707; compiled by 'chrisdo' on Fri Feb 19 08:07:34 UTC 2010
************************************************************/
2016-04-27 17:50:39,071 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 0 time(s).
2016-04-27 17:50:40,074 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 1 time(s).
2016-04-27 17:50:41,078 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 2 time(s).
2016-04-27 17:50:42,083 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 3 time(s).
2016-04-27 17:50:43,086 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 4 time(s).
2016-04-27 17:50:44,089 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 5 time(s).
2016-04-27 17:50:45,092 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 6 time(s).
2016-04-27 17:50:46,095 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 7 time(s).
2016-04-27 17:50:47,097 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 8 time(s).
2016-04-27 17:50:48,100 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /192.168.0.200:9000. Already tried 9 time(s).
2016-04-27 17:50:48,108 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException: Call to /192.168.0.200:9000 failed on local exception: java.net.NoRouteToHostException: 没有到主机的路由
at org.apache.hadoop.ipc.Client.wrapException(Client.java:775)
at org.apache.hadoop.ipc.Client.call(Client.java:743)
at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:220)
at com.sun.proxy.$Proxy2.getProtocolVersion(Unknown Source)
at org.apache.hadoop.ipc.RPC.getProxy(RPC.java:359)
at org.apache.hadoop.ipc.RPC.getProxy(RPC.java:346)
at org.apache.hadoop.ipc.RPC.getProxy(RPC.java:383)
at org.apache.hadoop.ipc.RPC.waitForProxy(RPC.java:314)
at org.apache.hadoop.ipc.RPC.waitForProxy(RPC.java:291)
at org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:269)
at org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:216)
at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:1283)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1238)
at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1246)
at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1368)
Caused by: java.net.NoRouteToHostException: 没有到主机的路由
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:404)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:304)
at org.apache.hadoop.ipc.Client$Connection.access$1700(Client.java:176)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:860)
at org.apache.hadoop.ipc.Client.call(Client.java:720)
... 13 more
2016-04-27 17:50:48,109 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down DataNode at slave1/192.168.0.201
************************************************************/
