For incompatible namespaceid error, there are two solutions available here.
http://www.michael-noll.com/tutorials/running-hadoop-on-ubuntu-linux-multi-node-cluster/ I ran into this same issue and second solution fixed it. ________________________________ From: anil gupta [mailto:[email protected]] Sent: Wednesday, August 08, 2012 1:36 PM To: [email protected] Subject: Re: Data node error This link might provide you some more information: http://mail-archives.apache.org/mod_mbox/hadoop-common-user/201203.mbox/%3ccaau13zhcmeuthva9opn9memyve9shxsd1gsdznzows3qrqz...@mail.gmail.com%3E HTH, Anil On Wed, Aug 8, 2012 at 12:56 AM, anil gupta <[email protected]<mailto:[email protected]>> wrote: Hi Prabhu, Did you clean the data dir on DataNodes? Whenever Namenode is formated the data directories of Datanodes needs to be cleaned up. As far as i remember it's the directory which you mention in dfs.data.dir in hdfs-site.xml file.You can do a google search for the error and you can get more details. (Sorry, i dont have access to my cluster conf right now for telling you the exact property). Thanks, Anil On Wed, Aug 8, 2012 at 12:49 AM, prabhu K <[email protected]<mailto:[email protected]>> wrote: Hi Users, I have formatted hadoop cluster, formatted successfully. after stop &start hadoop, i hit the jps command in master, getting fine, but in slave machine am not getting data node, while see the data node log file, i am getting following error. Data node(slave1): 2012-08-08 00:16:44,033 WARN org.apache.hadoop.hdfs.server.datanode.DataBlockScanner: Second Verification failed for blk_-3831635302961953167_1690. Exception : java.io<http://java.io>. IOException: Block blk_-3831635302961953167_1690 is not valid. at org.apache.hadoop.hdfs.server.datanode.FSDataset.getBlockFile(FSDataset.java:1072) at org.apache.hadoop.hdfs.server.datanode.FSDataset.getLength(FSDataset.java:1035) at org.apache.hadoop.hdfs.server.datanode.FSDataset.getVisibleLength(FSDataset.java:1045) at org.apache.hadoop.hdfs.server.datanode.BlockSender.<init>(BlockSender.java:94) at org.apache.hadoop.hdfs.server.datanode.BlockSender.<init>(BlockSender.java:81) at org.apache.hadoop.hdfs.server.datanode.DataBlockScanner.verifyBlock(DataBlockScanner.java:453) at org.apache.hadoop.hdfs.server.datanode.DataBlockScanner.verifyFirstBlock(DataBlockScanner.java:519) at org.apache.hadoop.hdfs.server.datanode.DataBlockScanner.run(DataBlockScanner.java:617) at java.lang.Thread.run(Thread.java:662) data node(slave2) 2012-08-08 13:03:50,195 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException: Incompatible namespaceIDs in /app/hadoop/tmp/dfs/data: namenode name spaceID = 1434906924; datanode namespaceID = 474761520 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) Please help me on this issue. Thanks, Prabhu. -- Thanks & Regards, Anil Gupta -- Thanks & Regards, Anil Gupta
