Hi, some queries,
1) If i set value of dfs.replication to 3 only in hadoop-site.xml of namenode(master) and then restart the cluster will this take effect. or i have to change hadoop-site.xml at all slaves ? 2) What can be possible cause of following error at a datanode. ? ERROR org.apache.hadoop.dfs.DataNode: java.io.IOException: Incompatible namespaceIDs in /mnt/hadoop28/HADOOP/hadoop-0.16.3/tmp/dir/hadoop-hadoop/dfs/data: namenode namespaceID = 1396640905; datanode namespaceID = 820259954 If my data node goes down due to above error, what should i do in following scenarios 1) i have some data on the currupted data node that i need to recover, how can i recover that data ? 2) If i dont care about the data, but i want the node back on the cluster, can i just delete the /mnt/hadoop28/HADOOP/hadoop-0.16.3/tmp and include the node back in the cluster? Regards Amit
