Hi Since upgrading to 0.18.0 I've noticed that restarting the datanode corrupts the hdfs so that the only option is to delete it and start again. I'm running hadoop in distributed mode, on a single host. It runs as the user hadoop and the hdfs is contained in a directory /home/hadoop/dfs.
When I restart hadoop using start-all.sh the datanode fails with the following message: STARTUP_MSG: args = [] STARTUP_MSG: version = 0.18.0 STARTUP_MSG: build = http://svn.apache.org/repos/asf/hadoop/core/branches/branch-0.18 -r 686010; compiled by 'hadoopqa' on Thu Aug 14 19:48:33 UTC 2008 ************************************************************/ 2008-09-01 12:06:55,871 ERROR org.apache.hadoop.dfs.DataNode: java.io.IOException: Found /home/hadoop/dfs/tmp/hadoop in /home/hadoop/dfs/tmp but it is not a file. at org.apache.hadoop.dfs.FSDataset$FSVolume.recoverDetachedBlocks(FSDataset.java:437) at org.apache.hadoop.dfs.FSDataset$FSVolume.<init>(FSDataset.java:310) at org.apache.hadoop.dfs.FSDataset.<init>(FSDataset.java:671) at org.apache.hadoop.dfs.DataNode.startDataNode(DataNode.java:277) at org.apache.hadoop.dfs.DataNode.<init>(DataNode.java:190) at org.apache.hadoop.dfs.DataNode.makeInstance(DataNode.java:2987) at org.apache.hadoop.dfs.DataNode.instantiateDataNode(DataNode.java:2942) at org.apache.hadoop.dfs.DataNode.createDataNode(DataNode.java:2950) at org.apache.hadoop.dfs.DataNode.main(DataNode.java:3072) 2008-09-01 12:06:55,872 INFO org.apache.hadoop.dfs.DataNode: SHUTDOWN_MSG: Running an fsck on the hdfs shows that it is corrupt, and the only way to fix it seems to be to delete it and reformat. Any suggestions? regards Barry -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.
