No locks available

[Adarsh Sharma]

Dear all,

I know this a silly mistake but not able to find the reason of the 
exception that causes one datanode to fail to start.

I mount  /hdd2-1 of a phsical machine into this VM and start 
datanode,tasktracker.

Datanode fails after few seconds.

Can someone tell  me  the root  cause.

Below is the exception :

2011-01-17 18:01:08,199 INFO 
org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting DataNode
STARTUP_MSG:   host = hadoop7/172.16.1.8
STARTUP_MSG:   args = []
STARTUP_MSG:   version = 0.20.2
STARTUP_MSG:   build = 
https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20 -r 
911707; compiled by 'chrisdo' on Fri Feb 19 08:07:34 UTC 2010
************************************************************/
2011-01-17 18:03:36,391 INFO 
org.apache.hadoop.hdfs.server.common.Storage: java.io.IOException: No 
locks available
       at sun.nio.ch.FileChannelImpl.lock0(Native Method)
       at sun.nio.ch.FileChannelImpl.tryLock(FileChannelImpl.java:881)
       at java.nio.channels.FileChannel.tryLock(FileChannel.java:962)
       at 
org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.tryLock(Storage.java:527)
       at 
org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.lock(Storage.java:505)
       at 
org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.analyzeStorage(Storage.java:363)
       at 
org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:112)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:298)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:216)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:1283)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1238)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1246)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1368)

2011-01-17 18:03:36,393 ERROR 
org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException: No 
locks available
       at sun.nio.ch.FileChannelImpl.lock0(Native Method)
       at sun.nio.ch.FileChannelImpl.tryLock(FileChannelImpl.java:881)
       at java.nio.channels.FileChannel.tryLock(FileChannel.java:962)
       at 
org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.tryLock(Storage.java:527)
       at 
org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.lock(Storage.java:505)
       at 
org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.analyzeStorage(Storage.java:363)
       at 
org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:112)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:298)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:216)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:1283)
       at 
org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1238)
"~/project/hadoop-0.20.2/logs/hadoop-hadoop-datanode-hadoop7.log" 42L, 
3141C                               1,1           Top




Thanks

Adarsh