Apache Hadoop Tutorial – Hadoop Distributed File System Overview
Every file is stored as Blocks in Hadoop Distributed File system.
The Default Block size is 64MB.
The NameNode contains information of all the DataNodes.
Replication Factor determines how many copies of the blocks have to be stored.The Replication factor is stored in the conf file. The default replication factor is 3
Can we change the replication factor of a particular file after storing on the HDFS?
I was thinking that if a particular file is most important and we want to increase its availibity.
Can we increase its replication factor?
yes we can do that one
Hi Mustaqeem,
Its possible even after you have written the file to HDFS.
You can use the following command to set the replication factor you like.
hdfs fs -setrep [-R]
Changes the replication factor of a file. -R option is for recursively increasing the replication factor of files within a directory.
Example:
hdfs fs -setrep -w 3 -R /user/hadoop/dir1
Thanx All 🙂
Hi,
Try this
$Hadoop_home/bin/hadoop dfs -setrep -w replication_value hdfs_file_path