Like many I have backups on external hard-drives, some are in HFS and others are in FAT32 or NTFS.

What happens to those backups with APFS ? I won't be able to access, read and write to or from them if I update to High Sierra to get APFS ? Thanks !

  • 2
    I don't understand the question. High Sierra will still be able to read FAT, HFS+ and NTFS partitions, and the system partition may be converted to APFS. What exactly do you want to read from where and why are you afraid that might cease to work?
    – deceze
    Sep 26, 2017 at 12:03
  • When you update your Mac(s) to High Sierra, only the internal flash devices you install High Sierra on will be converted to APFS. External devices will not be converted. If you are still concerned then unplug your external devices before upgrading. Sep 26, 2017 at 13:03
  • I mean, once I update to High Sierra / APFS, will I still be able to copy to and from the external non-APFS hard drives from/to my Mac ?
    – MFJC
    Sep 26, 2017 at 15:10
  • Will I be able to copy a file from my Mac (APFS) to my external hard drive (FAT32 / NTFS) for example.
    – MFJC
    Sep 26, 2017 at 15:12
  • And will I be able to copy a file from my external hard drive (FAT32 / NTFS) to my Mac (APFS) for example.
    – MFJC
    Sep 26, 2017 at 15:13

1 Answer 1


What happens to those backups with APFS?

Nothing happens.

Only the main internal drive is converted to APFS (and its contents are preserved anyways).

You will be able to use your external drives as before.

  • Thanks for your answer. The thing I struggle to grasp is that for example if you take an HFS drive, for example an external hard drive, with files on it. If you plug it on a NTFS or FAT computer under windows for example, you can't access it without tinkering and installing some drivers or software. Is it the same with APFS (on the computer's SSD) and FAT or NTFS external drives holding my backups. And if the FAT or NTFS drives are at least readable, can you execute and write from and to the drives using the APFS computer ?
    – MFJC
    Oct 3, 2017 at 9:59
  • What do you mean by "a NTFS or FAT computer"? There is no such thing as a "FAT computer" (nor NTFS). Those are file systems that can be used for partitions inside a disk. Oct 3, 2017 at 19:41
  • I beg to differ. I've got a FAT32-formatted flash drive that I use at the office for printing purposes, and since the update it has been rendered Read-Only. Nothing changed; the OS simply refuses to write to it now—which sucks double since the printer refuses to recognize Mac-formatted drives.
    – Kaji
    Oct 13, 2017 at 7:39
  • @Kaji I used a FAT drive yesterday. Those "become" read only usually when there is slight fear system damage. A format fixes the problem unless it's a hardware issue. Oct 13, 2017 at 7:53
  • @AndreaLazzarotto it's clear what I mean by "NTFS computer", you don't need a PHD to understand I'm, OF COURSE, talking about a computer with a NTFS filesystem ... I can't believe my question, yet so simple and basic, can't get a clear answer :/
    – MFJC
    Oct 16, 2017 at 9:34

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .