Time for action – formatting the NameNode
Before starting Hadoop in either pseudo-distributed or fully distributed mode for the first time, we need to format the HDFS filesystem that it will use. Type the following:
$ hadoop namenode -format
The output of this should look like the following:
$ hadoop namenode -format 12/10/26 22:45:25 INFO namenode.NameNode: STARTUP_MSG: /************************************************************ STARTUP_MSG: Starting NameNode STARTUP_MSG: host = vm193/10.0.0.193 STARTUP_MSG: args = [-format] … 12/10/26 22:45:25 INFO namenode.FSNamesystem: fsOwner=hadoop,hadoop 12/10/26 22:45:25 INFO namenode.FSNamesystem: supergroup=supergroup 12/10/26 22:45:25 INFO namenode.FSNamesystem: isPermissionEnabled=true 12/10/26 ...
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