Restoring NameNode metadata
If both the NameNode and the secondary NameNode were to suddenly go offline, you can restore the NameNode.
- Add a new host to your Hadoop cluster.
- Add the NameNode role to the host. Make sure it has the same hostname as the original NameNode.
Create a directory path for the NameNode
/dfs/nn/current), ensuring that the permissions are set correctly.
fsimagefile to the
Run the following command to create the md5 file for the fsimage.
md5sum fsimage > fsimage.md5
- Start the NameNode process.