http://www.w5j6stm77zs6652pgsij4awcjeel3eco7kvipheu6mtr623eyyehj4yd.onion/wiki/Encrypted_Images
Full Disk Encryption within the Virtual Machine [ edit ] When using FDE within the VM, never save (suspend/pause) the VM machine state, but instead shut it down completely. If this advice is ignored, the saved machine state could be stored outside of the encrypted image. This includes a RAM dump, which contains the encryption key required to decrypt the image. Upon resuming the VM, that stored file is not necessarily securely deleted, since it is virtualizer-specific.