HP XP7 Storage - Manual (Page 10)

Interoperability notes Software application
S-VOL, and journal volumes do not match, the journal data in the P-VOL is
not encrypted, and the security of the data cannot be guaranteed.
When enabling encryption for data written to a data pool with a V-VOL, use
a data pool that consists of encrypted volumes. Thin Provisioning, Smart Tiers, Thin
Provisioning Z, and Smart Tiers Z
Note: If encryption is set, encryption formatting for pool volumes and V-VOLs
is also required.
Encrypt the source LDEV and the target LDEV. The encryption states of the
source and target LDEVs must match for the EDKA feature to encrypt and
guarantee the security of the data on the target LDEV. Flex Copy XP
10 DKA Encryption Overview