I want to move my file from its path "/content/lastfm-dataset-1K/userid-timestamp-artid-artname-traid-traname.tsv" to the /user/root/ folder of hdfs and I don't know how
and i need to move it here:
You can use hdfs dfs -put command to upload files to hdfs
In docker, I want to copy a file README.md from an existing directory /opt/ibm/labfiles to a new one /input/tmp. I try this
hdfs dfs -put /opt/ibm/labfiles/README.md input/tmp
to no effect, because there seems to be no /input folder in the root. So I try to create it:
hdfs dfs -mkdir /input
mkdir:'/input': File exists
However, when I ls, there is no input file or directory
How can I create a folder and copy the file? Thank you!!
Please try hdfs dfs -ls / if you want to see there is an input folder that exists in HDFS at the root.
You cannot cd into an HDFS directory
It's also worth mentioning that the leading slash is important. In other words,
This will try to put the file in HDFS at /user/<name>/input/tmp
hdfs dfs -put /opt/ibm/labfiles/README.md input/tmp
While this puts the file at the root of HDFS
hdfs dfs -put /opt/ibm/labfiles/README.md /input/tmp
My aim is to read all the files that starts with "trans" in a directory and convert them into a single file and load that single file into HDFS location
my source directory is /user/cloudera/inputfiles/
Assume that inside that above directory , there are lot of file , but i need all the files that start with "trans"
my destination directory is /user/cloudera/transfiles/
So i tried this command below
hadoop dfs - getmerge /user/cloudera/inputfiles/trans* /user/cloudera/transfiles/records.txt
but the above command is not working .
If i try the below command then it works
hadoop dfs - getmerge /user/cloudera/inputfiles /user/cloudera/transfiles/records.txt
Any suggestion on how do i merge some files from a hdfs location and store that merged single file in another hdfs location
Below is the usage of getmerge command:
Usage: hdfs dfs -getmerge <src> <localdst> [addnl]
Takes a source directory and a destination file as input and
concatenates files in src into the destination local file.
Optionally addnl can be set to enable adding a newline character at the
end of each file.
It expects directory as first parameter.
you can try cat command like this:
hadoop dfs -cat /user/cloudera/inputfiles/trans* > /<local_fs_dir>/records.txt
hadoop dfs -copyFromLocal /<local_fs_dir>/records.txt /user/cloudera/transfiles/records.txt
I have a file sample.txt and i want to place it in hive warehouse directory (Not under the database xyz.db but directly into immediate subdirectory of warehouse). Is it possible?
To answer your question, since /user/hive/warehouse is just another folder on HDFS, you can move any file to the location without actually creating the file.
From the Hadoop Shell, you can achieve it by doing:
hadoop fs -mv /user/hadoop/sample.txt /user/hive/warehouse/
From the Hive Prompt, you can do that by giving this command:
!hadoop fs -mv /user/hadoop/sample.txt /user/hive/warehouse/
Here the first URL is the source location of your file and the next URL is the destination i.e. Hive Warehouse where you wish to move your file.
But such a situation does not generally occur in a real scenario.
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 .
bin/hadoop fs -get /hdfs/source/path /localfs/destination/path
bin/hadoop fs -copyToLocal /hdfs/source/path /localfs/destination/path
Point your web browser to HDFS WEBUI(namenode_machine:50070), browse to the file you intend to copy, scroll down the page and click on download the file.
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.
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)
Update: Hadoop is deprecated in Hadoop 3
use hdfs dfs -copyToLocal <input> <output>
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 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
This worked for me on my VM instance of Ubuntu.
hdfs dfs -copyToLocal [hadoop directory] [local directory]
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
if you are using docker you have to do the following steps:
copy the file from hdfs to namenode (hadoop fs -get output/part-r-00000 /out_text).
"/out_text" will be stored on the namenode.
copy the file from namenode to local disk by (docker cp namenode:/out_text output.txt)
output.txt will be there on your current working directory
bin/hadoop fs -put /localfs/destination/path /hdfs/source/path