hadoop useful CLI commands

$ hadoop fs -ls /                           (list all files in HDFS root directory)
$ hadoop job -list                         (find all running MapReduce jobs)
$ for svc in /etc/init.d/hadoop-0.20-*; do sudo $svc start; done    (Start up hadoop cluster)
$ for svc in /etc/init.d/hadoop-0.20-*; do sudo $svc stop; done    (Stop cluster)

(HDFS commands)
http://hadoop.apache.org/docs/r1.0.0/file_system_shell.html

(MapReduce commands)
http://hadoop.apache.org/docs/r1.0.0/commands_manual.html#job