启动Hadoop集群测试HBase时候，发现三台DataNode只启动成功了两台，未启动成功的那一台日志中出现了下列异常：
写道
2012-09-07 23:58:51,240 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: DataNode is shutting down: org.apache.hadoop.ipc.RemoteException: org.apache.hadoop.hdfs.protocol.UnregisteredDatanodeException: Data node 192.168.100.11:50010 is attempting to report storage ID DS-1282452139-218.196.207.181-50010-1344220553439. Node 192.168.100.12:50010 is expected to serve this storage.
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getDatanode(FSNamesystem.java:4608)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.processReport(FSNamesystem.java:3460)
at org.apache.hadoop.hdfs.server.namenode.NameNode.blockReport(NameNode.java:1001)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:563)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1388)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1384)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1382)
at org.apache.hadoop.ipc.Client.call(Client.java:1070)
at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:225)
at $Proxy5.blockReport(Unknown Source)
at org.apache.hadoop.hdfs.server.datanode.DataNode.offerService(DataNode.java:958)
at org.apache.hadoop.hdfs.server.datanode.DataNode.run(DataNode.java:1458)
at java.lang.Thread.run(Thread.java:722)
此异常是因为，两台DataNode的storageID出现了冲突，应该是因为我直接备份安装的原因吧。解决方法就是直接将出现异常的那台机器的data目录删除！
