what does this exception mean?
08/09/27 07:56:11 INFO mapred.JobClient: Task Id :
task_200809041356_0042_r_000000_2, Status : FAILED
org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find
any valid local directory for
task_200809041356_0042_r_000000_2/intermediate.9
at
org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:313)
at
org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:124)
at
org.apache.hadoop.io.SequenceFile$Sorter$MergeQueue.merge(SequenceFile.java:2851)
at
org.apache.hadoop.io.SequenceFile$Sorter.merge(SequenceFile.java:2586)
at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:352)
at
org.apache.hadoop.mapred.TaskTracker$Child.main(TaskTracker.java:2124)
