Shredding, also called secure deletion, is the process of overwriting the places where all the copies of an object were stored in such a way that none of the object data or metadata, including custom metadata, can be reconstructed. Each object has a shred setting that determines whether it is shredded when it’s deleted from the namespace.
Each namespace has a default shred setting. This is the setting applied to an object when it is stored in the namespace unless the shred setting is explicitly specified in the request to store the object. After an object is stored, users can change its shred setting from don’t shred to shred but not from shred to don’t shred.
When you create a namespace, its default shred setting is not to shred. You can change this setting at any time. Changing this setting does not affect existing objects in the namespace.