Back up HDFS metadata You can back up HDFS metadata without taking down either HDFS or the NameNodes. Prepare to back up the HDFS metadataRegardless of the solution, a full, up-to-date continuous backup of the namespace is not possible. Some of the most recent data is always lost. HDFS is not an Online Transaction Processing (OLTP) system. Most data can be easily recreated if you re-run Extract, Transform, Load (ETL) or processing jobs.Backing up NameNode metadataYou must back up the VERSION file and then back up the NameNode metadata.Back up HDFS metadata using Cloudera ManagerHDFS metadata backups can be used to restore a NameNode when both NameNode roles have failed. In addition, Cloudera recommends backing up HDFS metadata before a major upgrade.Restoring NameNode metadataIf both the NameNode and the secondary NameNode were to suddenly go offline, you can restore the NameNode.Restore HDFS metadata from a backup using Cloudera ManagerWhen both the NameNode hosts have failed, you can use Cloudera Manager to restore HDFS metadata.Perform a backup of the HDFS metadataYou can back up HDFS metadata without affecting the availability of NameNode.Parent topic: Backing up HDFS metadata
