DataNode: java.io.IOException: Incompatible namespaceIDs in /dfs/dfs/data: namenode namespaceID = 69

ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException: Incompatible namespaceIDs in /dfs/dfs/data: namenode namespaceID = 698802253; datanode namespaceID = 817847838

at org.apache.hadoop.hdfs.server.datanode.DataStorage.doTransition(DataStorage.java:232)

at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:147)

at org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:399)

at org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:309)

at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:1651)

at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1590)

at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1608)

at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:1734)

at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1751)

2013-07-04 01:07:14,090 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:

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

SHUTDOWN_MSG: Shutting down DataNode at localhost/127.0.0.1

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

2013-07-04 01:10:04,878 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG:

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

STARTUP_MSG: Starting DataNode

STARTUP_MSG: host = localhost/127.0.0.1

STARTUP_MSG: args = []

STARTUP_MSG: version = 1.1.2

STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.1 -r 1440782; compiled by 'hortonfo' on Thu Jan 31 02:03:24 UTC 2013

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

2013-07-04 01:10:05,319 INFO org.apache.hadoop.metrics2.impl.MetricsConfig: loaded properties from hadoop-metrics2.properties

2013-07-04 01:10:05,342 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source MetricsSystem,sub=Stats registered.

2013-07-04 01:10:05,343 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot period at 10 second(s).

2013-07-04 01:10:05,343 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: DataNode metrics system started

2013-07-04 01:10:05,554 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source ugi registered.

2013-07-04 01:10:06,455 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException: Incompatible namespaceIDs in /dfs/dfs/data: namenode namespaceID = 602361357; datanode namespaceID = 817847838

at org.apache.hadoop.hdfs.server.datanode.DataStorage.doTransition(DataStorage.java:232)

at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:147)

at org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:399)

at org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:309)

at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:1651)

at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1590)

at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1608)

at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:1734)

at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1751)

2013-07-04 01:10:06,477 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:

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

SHUTDOWN_MSG: Shutting down DataNode at localhost/127.0.0.1

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

2013-07-04 01:11:44,479 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG:

作为笔记记一下：这里面是namenode的namespaceIDs 与datanode的namespaceIDs 不一致，找到dfs的实际系统目录，打开name/current/VERSION与/data/curren/VERSION的文件，比较namespaceID的值，如果不一致，先修改namenode的值，再修改datanode的值，保持一致，然后重启hadoop就ok了