All drives in Series6E/Series7 and any configured external storage (MD1400 or MD2412) are self-encrypting (SED). However, encryption has to be turned on explicitly by the customer, so they can generate and manage their own encryption keys. NetWitness is not responsible for key generation and management and will not have access to customer's disk encryption keys. If the customer chooses to enable encryption, NetWitness recommends enabling it after completion of external storage configuration (if any).
Refer to Appendix B. Encrypt a Series 6E or Series 7 Core or Hybrid Host (encryptSedVd.py) for details on enabling encryption.