Introduction to Hadoop eco system - Overview of HDFS - Copying files from local to HDFS

We can copy files from the local file system to HDFS using commands like hdfs dfs -copyFromLocal or hdfs dfs -put. When copying files to HDFS, keep in mind that data in HDFS files cannot be directly updated or fixed; instead, files need to be moved to the local file system for any data modifications and then copied back to HDFS.

Files copied to HDFS are split into blocks and distributed across Datanodes based on block size and replication factor.

Key Concepts Explanation

Copying Files to HDFS

To copy files or directories from the local file system to HDFS, we can use commands like hdfs dfs -copyFromLocal or hdfs dfs -put. Optionally, hadoop fs can be used in place of hdfs dfs.

hdfs dfs -copyFromLocal [local_path] [hdfs_path]

Updating Data in HDFS

Data in files located in HDFS cannot be directly modified. Any changes needed would require moving the file to the local file system, making the modifications, and then copying the file back to HDFS.

Hands-On Tasks

  1. Copy files from the local file system to HDFS using hdfs dfs -copyFromLocal or hdfs dfs -put commands.
  2. Remove files from HDFS using hdfs dfs -rm.
  3. Copy files directly to a target folder in HDFS using -f option.

Conclusion

In this article, we covered the process of copying files from the local file system to HDFS, the limitations of updating data in HDFS files, and practical examples of using commands like hdfs dfs -copyFromLocal or hdfs dfs -put. We encourage readers to practice these tasks and engage with the community for further learning.

[embed the video here]

Key Concepts Explanation

Copying Files to HDFS

To copy files or directories from the local file system to HDFS, we can use commands like hdfs dfs -copyFromLocal or hdfs dfs -put. Optionally, hadoop fs can be used in place of hdfs dfs.

hdfs dfs -copyFromLocal [local_path] [hdfs_path]

Updating Data in HDFS

Data in files located in HDFS cannot be directly modified. Any changes needed would require moving the file to the local file system, making the modifications, and then copying the file back to HDFS.

Hands-On Tasks

  1. Copy files from the local file system to HDFS using hdfs dfs -copyFromLocal or hdfs dfs -put commands.
  2. Remove files from HDFS using hdfs dfs -rm.
  3. Copy files directly to a target folder in HDFS using -f option.

Conclusion

In this article, we covered the process of copying files from the local file system to HDFS, the limitations of updating data in HDFS files, and practical examples of using commands like hdfs dfs -copyFromLocal or hdfs dfs -put. We encourage readers to practice these tasks and engage with the community for further learning.

Watch the video tutorial here