exFAT support on macOS seems to have some bugs since exFAT drives may or maynot randomly get corrupted.
In my case, "not ejected properly" often casue the drive in Resource busy, Volume on xxx failed to mount, File system check exit code is 1, or Timed out waiting, when try to use both Disk Utility or diskutil
to mount, repair, or first aid the disk.
Possible fix is this:
- Use
diskutil list
to find the right drive id.- You want the id under the IDENTIFIER column, it should look like
disk1s1
. disk1
marks the entire Disk.disk1s1
ordisk1s2
marks each Volume.
- You want the id under the IDENTIFIER column, it should look like
- Usually, you want to check if the disk is occupied by one or many process.