Hello Cyril,
This is because your datanode has a different namespaceID from the
one which master(namenode) actually has. Have you formatted the HDFS
recently? Were you able to format it properly? Everytime you format HDFS,
NameNode generates new namespaceID, which should be same in both NameNodes
and DataNodes otherwise it won't be able to reach NameNode.
Warm Regards,
Tariq
https://mtariq.jux.com/
cloudfront.blogspot.com
On Wed, Mar 13, 2013 at 7:57 PM, Cyril Bogus <cyrilbo...@gmail.com> wrote:
> I am trying to start the datanode on the slave node but when I check the
> dfs I only have one node.
>
> When I check the logs on the slave node I find the following output.
>
> 2013-03-13 10:22:14,608 INFO
> org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG:
> /************************************************************
> STARTUP_MSG: Starting DataNode
> STARTUP_MSG: host = Owner-5/127.0.1.1
> STARTUP_MSG: args = []
> STARTUP_MSG: version = 1.0.4
> STARTUP_MSG: build =
> https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.0 -r
> 1393290; compiled by 'hortonfo' on Wed Oct 3 05:13:58 UTC 2012
> ************************************************************/
> 2013-03-13 10:22:15,086 INFO
> org.apache.hadoop.metrics2.impl.MetricsConfig: loaded properties from
> hadoop-metrics2.properties
> 2013-03-13 10:22:15,121 INFO
> org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source
> MetricsSystem,sub=Stats registered.
> 2013-03-13 10:22:15,123 INFO
> org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot
> period at 10 second(s).
> 2013-03-13 10:22:15,123 INFO
> org.apache.hadoop.metrics2.impl.MetricsSystemImpl: DataNode metrics system
> started
> 2013-03-13 10:22:15,662 INFO
> org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source ugi
> registered.
> 2013-03-13 10:22:15,686 WARN
> org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Source name ugi already
> exists!
> 2013-03-13 10:22:19,730 ERROR
> org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException:
> Incompatible namespaceIDs in /home/hadoop/hdfs/data: namenode namespaceID =
> 1683708441; datanode namespaceID = 606666501
> 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:385)
> at
> org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:299)
> at
> org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:1582)
> at
> org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1521)
> at
> org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1539)
> at
> org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:1665)
> at
> org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1682)
>
> 2013-03-13 10:22:19,731 INFO
> org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:
> /************************************************************
> SHUTDOWN_MSG: Shutting down DataNode at Owner-5/127.0.1.1
> ************************************************************/
>
> Thank you for any insights.
>
> Cyril
>
