HDFS

The Hadoop Distributed Filesystem

HDFS Architecture

HDFS Replicas

Upload a file to HDFS

To upload a file from local disk to HDFS:

hdfs dfs -put file.txt file.txt

It will copy the file to /user/username/file.txt in HDFS.

List files

To list files in HDFS:

hdfs dfs -ls

Lists the files in our HOME directory of HDFS /user/username/

To list files in the root directory:

hdfs dfs -ls /

Working with directories

Create a directory:

hdfs dfs -mkdir /tmp/test

Delete a directory:

hdfs dfs -rm -r -f /tmp/test

Working with files

Read a file:

hdfs dfs -cat file.txt

Download a file from HDFS to local disk:

hdfs dfs -get fichero.txt

Web File Explorer

You can easily access the HUE File Explorer from the WebUI:

Monitoring

You can easily access the NameNode UI from the WebUI: