I have 3 external drives. Drive-A is a nightly "smart update" bootable copy of my OS by Chronosync Drive-B is external file storage Drive-C is a copy of B "smart updated" nightly by Chronosync I know I can Filevault these drives, but I have questions and Google is no help. Q1: If I Filevault these drives, what happens upon boot? Are they unmounted until I manually mount manually? Q2: If I need to boot to the OS external clone, will I be able to boot to it over USB 3? Q3: Will drive B be able to copy to drive C like normal if they are both mounted properly? I'd prefer the encryption of the externals to be transparent unless the drives are powered off, as I can't always be around to mount the drives if they become unmounted. What is the practice for encrypting backup drives?