Introduction
Archival storage lets you store data on physical media with high storage density and low processing resources.
Implementing archival storage involves the following steps:
- Shut down the DataNode. 
- Assign the ARCHIVE storage type to DataNodes designed for archival storage. 
- Set HOT, WARM, or COLD storage policies on HDFS files and directories. 
- Restart the DataNode. 
If you update a storage policy setting on a file or directory, you must use the HDFS mover data migration tool to actually move blocks as specified by the new storage policy.

