Recover Hadoop NameNode Failure

In production, you should run the NameNodes in HA mode with a quorum of journalling nodes, or a shared HA-NFS storage for the edit log transaction files. If you do not want or use HA, you need to run the NN with at least two storage directories for both images and edit logs, with preferably one as a soft-mounted NFS mount point for automatic off-machine persistence of the name-system.

If you have just one storage directory and no HA configuration, then the best you can get is a past-period checkpoint - if you lose all the files. In case you didn't lose files, you can try a hadoop namenode -recover option as illustrated by this post to be able to recover the image plus some (or all) edits.