Fixing exFAT Drives on macOS

exFAT is a storage format created by Microsoft that is portable across platforms. This means you can read and write to exFAT-formatted drives from any operating system, including macOS.

Unfortunately, exFAT support on macOS can be unreliable. My external drives formatted with exFAT have occasionally become corrupted.

Disk Utility is often unable to repair this at first, but there is a way to fix it:

1. Use diskutil list to find the correct drive identifier.

• Look under the IDENTIFIER column for an entry like disk1s1.

2. Run sudo fsck_exfat -d <identifier>. For example: sudo fsck_exfat -d disk1s3

• The -d flag enables debug mode, so you’ll see your files as they’re processed.

3. If prompted with Main boot region needs to be updated. Yes/No?, answer YES.
4. Open Disk Utility again; you should now be able to repair the drive successfully.

See the Apple man page below for more details on the fsck_exfat utility.

References

• Fix corrupted exFAT disk macOS/OSX