Hadoop 비정상 종료 (SafeMode)

하둡 종료를 한번 잘못시켰더니........
하둡로그에 아래와 같은 로그가 발생.

구글검색결과 비정상적으로 종료 되었을경우에 안전모드로 들어간다. 
이경우에는 풀어 줄필요가 있음. 

2011-04-04 15:27:51,144 INFO org.apache.hadoop.mapred.JobTracker: problem cleaning system directory: hdfs://tedgelog1:9000/home/hadoop/hdfs/mapreduce/system

org.apache.hadoop.ipc.RemoteException: org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot delete /home/hadoop/hdfs/mapreduce/system. Name node is in safe mode.

# 再起動に失敗するとsafemodeになってしまい，HDFSのファイル操作ができなくなってしまいます．

# もし以下のようなメッセージが出た場合はsafemodeになってしまっています

put: org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create file/user/training/test.txt. Name node is in safe mode.

# safemodoを解除するには-safemode leaveを実行します

training@training-vm:~/tmp$ hadoop dfsadmin -safemode leave

Safe mode is OFF

참조: http://code.google.com/p/jatextmining/source/browse/wiki/Tutorial_with_cloudera.wiki?spec=svn23&r=23 

참조: http://omake.accense.com/wiki/Hadoop