Storage Encryption is an optional feature that you can enable for additional data protection. It is available on certain supported storage controllers and disk shelves that contain disks with built-in encryption functionality.
In a standard storage environment, data is written to disk in cleartext format. This makes the data vulnerable to potential exposure to unauthorized users when disks removed from a storage system are lost or stolen.
When you enable Storage Encryption, the storage system protects your data at rest by storing it on self-encrypting disks.
The authentication keys used by the self-encrypting disks are stored securely on external key management servers.