Apache Hadoop Tutorial – HDFS – Working With Replication Factors
In this post, I will explain about how you can change the Replication Factor of a file in HDFS
At first make sure, all components of Hadoop are started.
Create a new directory
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hadoop@kiran:~$ hadoop fs -mkdir "directory" /user/hadoop/ |
Copy two text files to the newly created Directory in HDFS
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hadoop@kiran:~$ hadoop fs -copyFromLocal "file1.txt" /user/hadoop/directory/ hadoop@kiran:~$ hadoop fs -copyFromLocal "file2.txt" /user/hadoop/directory/ |
Make a note of the Replication factor that is being set for the two files. By default the Replication Factor is 1 (as set in the conf file in my Hadoop Installation)
Now change the Replication factor of file “file1.txt” using
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hadoop@kiran:~$ hadoop fs -setrep -w 4 /user/hadoop/directory/file1.txt |
The replication factor of file “file1.txt” is now changed to 4.
To change Replication factor of all files in a given directory in HDFS use
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hadoop@kiran:~$ hadoop fs -setrep -w -R 3 /user/hadoop/directory/ |
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