hadoop datanode启动失败

 org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for Block pool <registering> (Datanode Uuid unassigned) service to zhanglingyun/127.0.0.1:9000. Exiting.

hadoop datanode 启动出错

FATAL org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for block pool Block pool BP-336454126-127.0.0.1-1419216478581 (storage id DS-445205871-127.0.0.1-50010-1419216613930)
service to /192.168.149.128:9000

org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.hdfs.server.protocol.DisallowedDatanodeException): Datanode denied communication with namenode: DatanodeRegistration(0.0.0.0, storageID=DS-445205871-127.0.0.1-50010-1419216613930, infoPort=50075, ipcPort=50020,
storageInfo=lv=-47;cid=CID-41993190-ade1-486c-8fe1-395c1d6f5739;nsid=1679060915;c=0)

        at org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager.registerDatanode(DatanodeManager.java:739)

        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.registerDatanode(FSNamesystem.java:3929)

        at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.registerDatanode(NameNodeRpcServer.java:948)

        at org.apache.hadoop.hdfs.protocolPB.DatanodeProtocolServerSideTranslatorPB.registerDatanode(DatanodeProtocolServerSideTranslatorPB.java:90)

        at org.apache.hadoop.hdfs.protocol.proto.DatanodeProtocolProtos$DatanodeProtocolService$2.callBlockingMethod(DatanodeProtocolProtos.java:24079)

        at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:585)

        at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928)

        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2048)

        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2044)

        at java.security.AccessController.doPrivileged(Native Method)

        at javax.security.auth.Subject.doAs(Subject.java:415)

        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491)

        at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2042)
 
产生原因，一开始配置文件中使用的是localhost ,后来改成Ip, 再次格式化了namenode引起的。
解决方案：
1，删除dfs.namenode.name.dir和dfs.datanode.data.dir 目录下的所有文件
2，修改hosts
[tank@localhost hadoop-2.2.0]$ cat /etc/hosts

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4

::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.149.128 localhost
3,重新格式化:bin/hadoop namenode -format
4,启动
附：如果没有删除datanode 格式化了namenode，则会引起datanode与namenode版本号不一致的错误
解决方案：
修改dfs.datanode.data.dir下的current/version中的clusterID与
dfs.namenode.name.dir的一致重启即可。

原文链接：http://www.cnblogs.com/tankaixiong/p/4177832.html