Orphaned snapshots

When you edit or delete a snapshot policy, the snapshots for the files, directories, or tables that were removed from the snapshot policy are retained. These are known as orphaned snapshots. These snapshots are not deleted automatically because they are no longer associated with a snapshot policy.

You can identify and delete these orphaned snapshots manually through Cloudera Manager, or by creating a command-line script that uses the HDFS or HBase snapshot commands.

To avoid orphaned snapshots, you can choose one of the following methods depending on your requirements.

Delete the snapshots before you edit or delete the associated snapshot policy.
Cloudera Manager assigns the prefix cm-auto which is followed by a globally unique identifier (GUID) for every HDFS snapshot policy. You can view the snapshot prefix in the policy summary in the policy list, and in the delete modal window.
note
Before you delete a snapshot policy, ensure that you record the snapshot names in the snapshot policy and the cm-auto-guid of the snapshot policy. This is because you cannot determine the snapshot names in the snapshot policy and the cm-auto-guid of the snapshot policy after you delete the snapshot policy, and the snapshot names also do not contain any recognizable references to its snapshot policy.
Identify the orphaned snapshots for a deleted snapshot policy using its cm-auto-guid, and delete the snapshots.