I just encrypted my boot drive on my desktop iMac with FileVault. I have three external disks that I would like to encrypt, especially since they're a lot easier to steal than my iMac, which is bolted to an LCD arm on the wall. I have the following disks: LaCie Little Big Disk Thunderbolt 2 Newertech 4TB Newertech 6 TB When I tried encrypting the LaCie, it said "You can’t convert an AppleRAID volume to Core Storage." The LaCie is a set of 2 PCIe SSDs preconfigured in RAID 0. When I tried to encrypt the Newertech hard drives, I got this error message: "A Recovery System for the targeted disk is required." How can I encrypt these external disks? There's not much point in having my iMac encrypted when I have backup drives sitting right next to it that are not encrypted and far easier to run off with if someone broke in to the house.