Hadoop Snapshot Management

Introduction

Welcome to the magical world of Hadoop Snapshot Management! In this lab, you will embark on a journey through a enchanting forest where you will meet a mysterious tree spirit known as Leafa. Your goal is to learn the art of managing snapshots in Hadoop HDFS while exploring the wonders of this mystical realm.

Creating a Snapshot

In this step, you will learn how to create a snapshot of a directory in HDFS.

1. Open a terminal and switch to the hadoop user:

   su - hadoop
   

2. Create a directory in HDFS:

   hdfs dfs -mkdir /user/hadoop/snapshot_demo
   

3. Populate the directory with some sample files:

   echo "Hello, World" > /home/hadoop/sample.txt
   

   hdfs dfs -put /home/hadoop/sample.txt /user/hadoop/snapshot_demo/
   

4. Allow snapshots on the directory:

   hdfs dfsadmin -allowSnapshot /user/hadoop/snapshot_demo
   

5. Verify that the directory is snapshottable:

   hdfs lsSnapshottableDir
   

6. Create a snapshot of the directory:

   hdfs dfs -createSnapshot /user/hadoop/snapshot_demo snapshot1
   

7. Verify the snapshot creation:

   hdfs dfs -ls /user/hadoop/snapshot_demo/.snapshot/snapshot1
   

Restoring a Snapshot

In this step, you will learn how to restore a directory from a snapshot in HDFS.

1. Create a directory in HDFS:

   hdfs dfs -mkdir /user/hadoop/restored_snapshot_demo
   

2. Restore the directory from the created snapshot:

   hdfs dfs -cp /user/hadoop/snapshot_demo/.snapshot/snapshot1 /user/hadoop/restored_snapshot_demo
   

3. Verify the contents of the restored directory:

   hdfs dfs -cat /user/hadoop/restored_snapshot_demo/snapshot1/sample.txt
   

Deleting a Snapshot

In this step, you will learn how to delete a previously created snapshot in Hadoop's HDFS.

1. Delete the snapshot created in the first step:

   hdfs dfs -deleteSnapshot /user/hadoop/snapshot_demo snapshot1
   

2. Verify the snapshot deletion:

   hdfs dfs -ls /user/hadoop/snapshot_demo/.snapshot
   

Summary

In this lab, we delved into the realm of Hadoop Snapshot Management by creating, restoring, and deleting snapshots in HDFS. Through these hands-on exercises, you gained practical experience in handling snapshots, a crucial aspect of managing data in Hadoop. By mastering snapshot management, you are now equipped with a powerful tool for data backup and recovery in your Hadoop ecosystem. Happy exploring the magical world of Hadoop!