mapred.local.dir is under /hadoop/mapred defs.data.dir is /hadoop./dfs. The
logs showing
011-04-11 14:34:10,987 INFO org.apache.hadoop.ipc.Server: IPC Server
listener on 50020: starting
2011-04-11 14:34:10,987 INFO org.apache.hadoop.ipc.Server: IPC Server
handler 0 on 50020: starting
2011-04-11 14:34:10,988 INFO org.apache.hadoop.ipc.Server: IPC Server
handler 1 on 50020: starting
2011-04-11 14:34:10,988 INFO
org.apache.hadoop.hdfs.server.datanode.DataNode: dnRegistration =
DatanodeRegistration(had41.xxx:50010,
storageID=DS-922075132-69.170.130.173-50010-1297386088418, infoPort=50075,
ipcPort=50020)
2011-04-11 14:34:10,988 INFO org.apache.hadoop.ipc.Server: IPC Server
handler 2 on 50020: starting
2011-04-11 14:34:11,021 INFO
org.apache.hadoop.hdfs.server.datanode.DataNode: DatanodeRegistration(
69.170.130.173:50010,
storageID=DS-922075132-69.170.130.173-50010-1297386088418, infoPort=50075,
ipcPort=50020)In DataNode.run, data =
FSDataset{dirpath='/hadoop/dfs/current'}
2011-04-11 14:34:11,021 INFO
org.apache.hadoop.hdfs.server.datanode.DataNode: using BLOCKREPORT_INTERVAL
of 3600000msec Initial delay: 0msec
2011-04-11 14:34:15,545 INFO
org.apache.hadoop.hdfs.server.datanode.DataNode: BlockReport of 110651
blocks got processed in 4493 msecs
2011-04-11 14:34:15,545 INFO
org.apache.hadoop.hdfs.server.datanode.DataNode: Starting Periodic block
scanner.
2011-04-11 14:34:15,692 INFO
org.apache.hadoop.hdfs.server.datanode.DataNode: Deleting block
blk_-9213431071914219029_3395500 file
/hadoop/dfs/current/subdir7/subdir26/blk_-9213431071914219029
then followed by all the blocks in the dfs/current directory. Seems to me
hadoop just want to invalidate all the blocks in that box by deleting all of
it.
On Tue, Apr 12, 2011 at 9:17 AM, Harsh J <ha...@cloudera.com> wrote:
> Apart from ensuring all that others here have said, are your
> mapred.local.dir and dfs.data.dir pointing to the same directory by
> any chance? If that so happens, the tasktracker could potentially wipe
> out the datanode directories when restarted.
>
> On Tue, Apr 12, 2011 at 8:16 PM, felix gao <gre1...@gmail.com> wrote:
> > What reason/condition would cause a datanode’s blocks to be removed?
> Our
> > cluster had a one of its datanodes crash because of bad RAM. After the
> > system was upgraded and the datanode/tasktracker brought online the next
> day
> > we noticed the amount of space utilized was minimal and the cluster was
> > rebalancing blocks to the datanode. It would seem the prior blocks were
> > removed. Was this because the datanode was declared dead? What is the
> > criteria for a namenode to decide (Assuming its the namenode) when a
> > datanode should remove prior blocks?
>
> --
> Harsh J
>
