Starting HDFS

Now we must format the file system that we just configured:

user@namenode:hadoop$ bin/hadoop namenode -format

This process should only be performed once. When it is complete, we are free to start the distributed file system:

user@namenode:hadoop$ bin/start-dfs.sh

This command will start the NameNode server on the master machine (which is where the start-dfs.sh script was invoked). It will also start the DataNode instances on each of the slave machines. In a single-machine "cluster," this is the same machine as the NameNode instance. On a real cluster of two or more machines, this script will ssh into each slave machine and start a DataNode instance.

1 comment :

  1. A table is the basic unit of data storage in an oracle database. The table of a database hold all of the user accesible data. Table data is stored in rows and columns. But what is all about the clusters and how to handle it using oracle database system? Expecting a right answer from you. By the way you are maintaining a great blog. Thanks for sharing this in here.
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