HDFS safemode 설정

간혹 namenode 실행할 때, safemode 가 on 상태로 되어있어 namenode 가 실행되지 않는 경우가 있다. 이럴 땐 강제로 safemode 를 off 상태로 변경해주어야 한다.

Safemode 끄기

$ hdfs dfsadmin -safemode leave
 
Usage: hdfs [--config confdir] [--loglevel loglevel] COMMAND
Usage: hadoop [--config confdir] COMMAND
where COMMAND is one of:
  namenode -format     format the DFS filesystem
  secondarynamenode    run the DFS secondary namenode
  namenode             run the DFS namenode
  datanode             run a DFS datanode
  dfsadmin             run a DFS admin client
  mradmin              run a Map-Reduce admin client
  fsck                 run a DFS filesystem checking utility
  fs                   run a generic filesystem user client
  balancer             run a cluster balancing utility
  fetchdt              fetch a delegation token from the NameNode
  jobtracker           run the MapReduce job Tracker node
  pipes                run a Pipes job
  tasktracker          run a MapReduce task Tracker node
  historyserver        run job history servers as a standalone daemon
  job                  manipulate MapReduce jobs
  queue                get information regarding JobQueues
  version              print the version
  jar <.jar>            run a jar file
  distcp <srcurl> <desturl> copy file or directories recursively
  archive -archiveName NAME -p &lt;parent path&gt; &lt;src&gt;* &lt;dest&gt; create a hadoop archive
  classpath            prints the class path needed to get the
                       Hadoop jar and the required libraries
  daemonlog            get/set the log level for each daemon
 or
  CLASSNAME            run the class named CLASSNAME
Most commands print help when invoked w/o parameters.