I have a lot of data on my external drive.
The file system is the exFAT.
I believe it is not possible to encrypt that filesystem with FileVault.

Do you know how (tool maybe) to encrypt exFAT on an external drive without changing filesystem?

1 Answer 1


I confirm that drives that use the FAT or the exFAT file format can’t be encrypted using FileVault.

Therefore, if this can help, I suggest you to create two partitions of the device using two different file format.

  • Thank you for quick answer @Mattia. Sadly It is hard for me because I don't have additional disk to migrate 2T data to make partitioning.
    – Holy Sync
    Feb 17, 2016 at 13:30
  • 2
    This answer is correct. FileVault disk encryption requires your disk to be GPT (GUID partition table) and the volume type to be OSX extended (journaled JHFS+). I believe that an exFAT volume is not dynamically resizeable, so it would not be possible to create a small encrypted JHFS+ volume and progressively migrate files from one volume to the other whilst resizing both volumes (i.e. - growing the encrypted volume and shrinking the exFAT volume). You will need to borrow/buy more disk space. You could temporarily use cloud-based storage (eg BackBlaze) if your internet connection is very fast. Feb 17, 2016 at 18:46
  • I did as you suggested. I borrowed the other disk made a copy and reformat to HFS+ with encryption. Thank you!
    – Holy Sync
    Feb 18, 2016 at 13:13
  • @HolySync I'm glad to know that.
    – rebatoma
    Feb 18, 2016 at 14:20

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