[hadoop] How to copy file from HDFS to the local file system

How to copy file from HDFS to the local file system . There is no physical location of a file under the file , not even directory . how can i moved them to my local for further validations.i am tried through winscp .

In Hadoop 2.0,

hdfs dfs -copyToLocal <hdfs_input_file_path> <output_path>

where,

• hdfs_input_file_path maybe obtained from http://<<name_node_ip>>:50070/explorer.html

• output_path is the local path of the file, where the file is to be copied to.

• you may also use get in place of copyToLocal.

you can accomplish in both these ways.

1.hadoop fs -get <HDFS file path> <Local system directory path>
2.hadoop fs -copyToLocal <HDFS file path> <Local system directory path>

Ex:

My files are located in /sourcedata/mydata.txt I want to copy file to Local file system in this path /user/ravi/mydata

hadoop fs -get /sourcedata/mydata.txt /user/ravi/mydata/

if you are using docker you have to do the following steps:

1. copy the file from hdfs to namenode (hadoop fs -get output/part-r-00000 /out_text). "/out_text" will be stored on the namenode.

2. copy the file from namenode to local disk by (docker cp namenode:/out_text output.txt)

3. output.txt will be there on your current working directory

If your source "file" is split up among multiple files (maybe as the result of map-reduce) that live in the same directory tree, you can copy that to a local file with:

hadoop fs -getmerge /hdfs/source/dir_root/ local/destination

In order to copy files from HDFS to the local file system the following command could be run:

hadoop dfs -copyToLocal <input> <output>

• <input>: the HDFS directory path (e.g /mydata) that you want to copy
• <output>: the destination directory path (e.g. ~/Documents)

1.- Remember the name you gave to the file and instead of using hdfs dfs -put. Use 'get' instead. See below.

$hdfs dfs -get /output-fileFolderName-In-hdfs

This worked for me on my VM instance of Ubuntu.

hdfs dfs -copyToLocal [hadoop directory] [local directory]

bin/hadoop fs -put /localfs/destination/path /hdfs/source/path