启动hadoop 2.6遇到的datanode启动不了

2017-10-12 17:54:08,123 INFO org.apache.hadoop.hdfs.server.common.Storage: Lock on /usr/hadoop/temp/dfs/data/in_use.lock acquired by nodename 6268@soc71

2017-10-12 17:54:08,124 FATAL org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for Block pool <registering> (Datanode Uuid unassigned) service to soc71/172.16.10.71:9000. Exiting. 

java.io.IOException: Incompatible clusterIDs in /usr/hadoop/temp/dfs/data: namenode clusterID = CID-2b0764df-b850-4f80-862c-1cfdcf6b9199; datanode clusterID = CID-37fc5257-9eba-49d1-83ea-845f5b0d4b24
at org.apache.hadoop.hdfs.server.datanode.DataStorage.doTransition(DataStorage.java:646)
at org.apache.hadoop.hdfs.server.datanode.DataStorage.addStorageLocations(DataStorage.java:320)
at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:403)
at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:422)
at org.apache.hadoop.hdfs.server.datanode.DataNode.initStorage(DataNode.java:1311)
at org.apache.hadoop.hdfs.server.datanode.DataNode.initBlockPool(DataNode.java:1276)
at org.apache.hadoop.hdfs.server.datanode.BPOfferService.verifyAndSetNamespaceInfo(BPOfferService.java:314)
at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.connectToNNAndHandshake(BPServiceActor.java:220)
at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.run(BPServiceActor.java:828)
at java.lang.Thread.run(Thread.java:745)

2017-10-12 17:54:08,125 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Ending block pool service for: Block pool <registering> (Datanode Uuid unassigned) service to soc71/172.16.10.71:9000

2017-10-12 17:54:08,226 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Removed Block pool <registering> (Datanode Uuid unassigned)

2017-10-12 17:54:10,226 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Exiting Datanode

2017-10-12 17:54:10,227 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 0

2017-10-12 17:54:10,228 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG: 

/************************************************************

SHUTDOWN_MSG: Shutting down DataNode at soc71/172.16.10.71
************************************************************/

从日志上看，加粗的部分说明了问题
datanode的clusterID 和 namenode的clusterID 不匹配。

解决办法:
根据日志中的路径，cd /home/hadoop/tmp/dfs
能看到 data和name两个文件夹，
将name/current下的VERSION中的clusterID复制到data/current下的VERSION中，覆盖掉原来的clusterID