You are required to use data-at-rest encryption on a NetApp ONTAP system.

[Reference:https://docs.netapp.com/ontap-9/index.jsp?topic=%2Fcom.netapp.doc.pow-nve%2FGUID-EAD13D8E-0219-45B6-A2C6-B25B76C9CA1A.html, NetApp Volume Encryption (NVE), NetApp self encrypting drives (SEDs), and NetApp Aggregate Encryption (NAE) are three technologies that provide data-at-rest encryption on a NetApp ONTAP system. They also allow you to maintain cross-volume storage efficiencies, such as deduplication and compression, across encrypted volumes., ]