A few weeks ago I told all of my three external hard drives to encrypt. This went well, macOS (10.13.4) converted them to a APFS formatted encrypted volume, except for one drive. This drive doesn't complete it's encryption as it seems. Right-clicking on it shows a greyed-out entry for the "encrypt volume" command. I tried decrypting it using the cli by executing
diskutil apfs decryptVolume /dev/disk11s1
Which is answered with an error
Starting background decryption of disk11s1 using the "Disk" crypto user as authorization Error starting background decryption of APFS Volume: The given APFS Volume is already encrypting or decrypting (-69573)
It seems as if the encryption got stuck somehow.
Is there a way to cancel or restart that process? Or do I have to copy all data from that volume to another and re-format the drive? I know that even Apple doesn't recommend APFS for hard discs, only for SSDs. Maybe that's the best way to go, right? I could reformat the drive with an encrypted HFS+ file system.