Shredding

Shredding, also called secure deletion, is the process of deleting an object and overwriting the places where its copies were stored in such a way that none of its data or metadata, including custom metadata, can be reconstructed.

Every object has a shred setting that determines whether it will be shredded when it’s deleted.

With HTTP, the shred settings for an object are returned by the X-HCP-Shred response header. The shred setting values are:

false — Don’t shred.

true — Shred following deletion.

With WebDAV, CIFS, or NFS, you view the shred setting for an object in the shred.txt metafile. The shred setting values in this metafile are:

0 (zero) — Don’t shred.

1 (one) — Shred following deletion.

Default shred settings

The namespace is configured with a default shred setting. When an object is stored in the namespace, the object inherits this setting. With HTTP, you can override the default shred setting by specifying a different shred setting when you store the object. For more information on using HTTP to override default shred settings, see Specifying metadata on object creation.

Changing shred settings

You can change the shred setting for an existing object from false to true (or 0 to 1) but not from true to false (or 1 to 0).

For information on changing shred settings with HTTP, see Modifying object metadata.

With WebDAV, CIFS, or NFS, you change the shred setting for an object by overwriting its shred.txt metafile. In the new file, you specify only the new value.

Tip:  

With Windows and Unix, you can also use the echo command to insert the new value into the shred.txt metafile.

As a general rule, if you mark an object for shredding, you should mark all other objects with the same content for shredding as well.

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