Docsity
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Docsity AI
Docsity AI
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search for your university

Find the specific documents for your university's exams

Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

Hadoop HDFS Command Cheatsheet, Cheat Sheet of Advanced Computer Programming

Union CollegeAdvanced Computer Programming

HDFS commands for list files, read/write files, upload/download files, file management, filesystem, administration etc

Typology: Cheat Sheet

2020/2021

Uploaded on 04/27/2021

lovefool
lovefool 🇬🇧

4.5

(21)

292 documents

1 / 2

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Hadoop HDFS Command Cheatsheet
List Files
hdfs dfs -ls /
List all the files/directories for the given hdfs destination path.
hdfs dfs -ls -d /hadoop
Directories are listed as plain files. In this case, this command will list
the details of hadoop folder.
hdfs dfs -ls -h /data
Format file sizes in a human-r eadable fashion (eg 64.0m instead of
67108864).
hdfs dfs -ls -R /hadoop
Recursively list all files in hadoop directory and all subdirectories in
hadoop directory.
hdfs dfs -ls /hadoop/dat*
List all the files matching the pattern. In this case, it will list all the
files inside hadoop directory which starts with 'dat'.
Read/Write Files
hdfs dfs -text /hadoop/derby.log
HDFS Command that takes a source file and outputs the file in text
format on the terminal. The allowed formats are zip and
TextRecordInputStream.
hdfs dfs -cat /hadoop/test
This command will display the content of the HDFS file test on your
stdout .
hdfs dfs -appendToFile /home/ubuntu/test1
/hadoop/text2
Appends the content of a local file test1 to a hdfs file test2.
Upload/Download Files
hdfs dfs -put /home/ubuntu/sample /hadoop
Copies the file from local file system to HDFS.
hdfs dfs -put -f /home/ubuntu/sample /hadoop
Copies the file from local file system to HDFS, and in case the local
already exits in the given destination path, using -f option with put
command will overwrite it.
hdfs dfs -put -l /home/ubuntu/sample /hadoop
Copies the file from local file system to HDFS. Allow DataNode to
lazily persist the file to disk. Forces replication f actor of 1.
hdfs dfs -put -p /home/ubuntu/sampl e /hadoop
Copies the file from local file system to HDFS. Passing -p preserves
access and modification times, ownership and the mode.
hdfs dfs -get /newfile /home/ubuntu/
Copies the file from HDFS to local file system.
hdfs dfs -get -p /newfile /home/ubuntu/
Copies the file from HDFS to local file system. Passing -p preserves
access and modification times, ownership and the mode.
hdfs dfs -get /hadoop/*.txt /home/ubuntu/
Copies all the files matching the pattern from local file system to
HDFS.
hdfs dfs -copyFromLocal /home/ubuntu/sample /hadoop
Works similarly to the put command, except that the source is
restricted to a local file reference.
hdfs dfs -copyToLocal /newfile /home/ubuntu/
Works similarly to the put command, except that the destination is
restricted to a local file reference.
hdfs dfs -moveFromLocal /home/ubuntu/sample /hadoop
Works similarly to the put command, except that the source is
deleted after it's copied.
File Management
hdfs dfs -cp /hadoop/file1 /hadoop1
Copies file from source to destination on HDFS. In this case, copying
file1 from hadoop directory to hadoop1 directory.
hdfs dfs -cp -p /hadoop/file1 /hadoop1
Copies file from source to destination on HDFS. P assing -p preserves
access and modification times, ownership and the mode.
hdfs dfs -cp -f /hadoop/file1 /hadoop1
Copies file from source to destination on HDFS. Passing -f overwrites
the destination if it already exists.
hdfs dfs -mv /hadoop/file1 /hadoop1
Move files that match the specified file pattern <src> to a destination
<dst>. When moving multiple files, the des tination must be a
directory.
hdfs dfs -rm /hadoop/file1
Deletes the file (sends it to the trash).
pf2

Partial preview of the text

Download Hadoop HDFS Command Cheatsheet and more Cheat Sheet Advanced Computer Programming in PDF only on Docsity!

Hadoop HDFS Command Cheatsheet

List Files

hdfs dfs - ls / List all the files/directories for the given hdfs destination path. hdfs dfs - ls - d /hadoop Directories are listed as plain files. In this case, this command will list the details of hadoop folder. hdfs dfs - ls - h /data Format file sizes in a human-readable fashion (eg 64.0m instead of 67108864). hdfs dfs - ls - R /hadoop Recursively list all files in hadoop directory and all subdirectories in hadoop directory. hdfs dfs - ls /hadoop/dat* List all the files matching the pattern. In this case, it will list all the files inside hadoop directory which starts with 'dat'.

Read/Write Files

hdfs dfs - text /hadoop/derby.log HDFS Command that takes a source file and outputs the file in text format on the terminal. The allowed formats are zip and TextRecordInputStream. hdfs dfs - cat /hadoop/test This^ command will display the content of the HDFS file test on your stdout. hdfs dfs - appendToFile /home/ubuntu/test /hadoop/text Appends the content of a local file test1 to a hdfs file test2.

Upload/Download Files

hdfs dfs - put /home/ubuntu/sample /hadoop Copies the file from local file system to HDFS. hdfs dfs - put - f /home/ubuntu/sample /hadoop Copies the file from local file system to HDFS, and in case the local already exits in the given destination path, using - f option with put command will overwrite it. hdfs dfs - put - l /home/ubuntu/sample /hadoop Copies the file from local file system to HDFS. Allow DataNode to lazily persist the file to disk. Forces replication factor of 1. hdfs dfs - put - p /home/ubuntu/sample /hadoop Copies the file from local file system to HDFS. Passing - p preserves access and modification times, ownership and the mode. hdfs dfs - get /newfile /home/ubuntu/ Copies the file from HDFS to local file system. hdfs dfs - get - p /newfile /home/ubuntu/ Copies the file from HDFS to local file system. Passing - p preserves access and modification times, ownership and the mode. hdfs dfs - get /hadoop/*.txt /home/ubuntu/ Copies all the files matching the pattern from local file system to HDFS. hdfs dfs - copyFromLocal /home/ubuntu/sample /hadoop Works similarly to the^ put^ command, except that the source is restricted to a local file reference. hdfs dfs - copyToLocal /newfile /home/ubuntu/ Works similarly to the^ put^ command, except that the destination is restricted to a local file reference. hdfs dfs - moveFromLocal /home/ubuntu/sample /hadoop Works similarly to the put command, except that the source is deleted after it's copied.

File Management

hdfs dfs - cp /hadoop/file1 /hadoop Copies file from source to destination on HDFS. In this case, copying file1 from hadoop directory to hadoop1 directory. hdfs dfs - cp - p /hadoop/file1 /hadoop Copies file from source to destination on HDFS. Passing - p preserves access and modification times, ownership and the mode. hdfs dfs - cp - f /hadoop/file1 /hadoop1 Copies^ file from source to destination on HDFS. Passing^ - f overwrites the destination if it already exists. hdfs dfs - mv /hadoop/file1 /hadoop Move files that match the specified file pattern to a destination . When moving multiple files, the destination must be a directory. hdfs dfs - rm /hadoop/file1 Deletes the file (sends it to the trash).

hdfs dfs - rm - r /hadoop hdfs dfs - rm - R /hadoop hdfs dfs - rmr /hadoop Deletes the directory and any content under it recursively. hdfs dfs - rm - skipTrash /hadoop The^ - skipTrash option will bypass trash, if enabled, and delete the specified file(s) immediately. hdfs dfs - rm - f /hadoop If the file does not exist, do not display a diagnostic message or modify the exit status to reflect an error. hdfs dfs - rmdir /hadoop1 Delete a directory. hdfs dfs - mkdir /hadoop2 Create a directory in specified HDFS location. hdfs dfs - mkdir - f /hadoop Create a directory in specified HDFS location. This command does not fail even if the directory already exists. hdfs dfs - touchz /hadoop Creates a file of zero length at with current time as the timestamp of that . Ownership and Validation hdfs dfs - checksum /hadoop/file Dump checksum information for files that match the file pattern to stdout. hdfs dfs - chmod 755 /hadoop/file1 Changes permissions of the file. hdfs dfs - chmod - R 755 /hadoop Changes permissions of the files recursively. hdfs dfs - chown ubuntu:ubuntu /hadoop Changes owner of the file. 1st ubuntu in the command is owner and 2nd one is group. hdfs dfs - chown - R ubuntu:ubuntu /hadoop Changes owner of the files recursively. hdfs dfs - chgrp ubuntu /hadoop Changes group association of the file. hdfs dfs - chgrp - R ubuntu /hadoop Changes group association of the files recursively. Filesystem hdfs dfs - df /hadoop Shows the capacity, free and used space of the filesystem. hdfs dfs - df - h /hadoop Shows the capacity, free and used space of the filesystem.^ - h parameter Formats the sizes of files in a human-readable fashion. hdfs dfs - du /hadoop/file Show the amount of space, in bytes, used by the files that match the specified file pattern. hdfs dfs - du - s /hadoop/file Rather than showing the size of each individual file that matches the pattern, shows the total (summary) size. hdfs dfs - du - h /hadoop/file Show the amount of space, in bytes, used by the files that match the specified file pattern. Formats the sizes of files in a human-readable fashion. Administration hdfs balancer - threshold 30 Runs a cluster balancing utility. Percentage of disk capacity. This overwrites the default threshold. hadoop version To check the vesrion of Hadoop. hdfs fsck / It checks the health of the Hadoop file system. hdfs dfsadmin - safemode leave The command to turn off the safemode of NameNode. hdfs dfsadmin - refreshNodes Re-read the hosts and exclude files to update the set of Datanodes that are allowed to connect to the Namenode and those that should be decommissioned or recommissioned. hdfs namenode - format Formats the NameNode.