"The disk you inserted was not readable by this computer"

[tbjem0013]

I have 2 hard drives which I copy all my Final Cut Pro projects to.

I use these drives with Windows 10 as well, so they are in exFAT.

One of the drives now comes up with this message when I boot up: "The disk you inserted was not readable by this computer." It gives options to Initialize, Ignore, and Eject

I have NOT selected Initialize, because I have files on that drive that I don't want to erase. What happens if I eject?

In Disk Utility the drive does show up, however it shows it as 1 big Untitled partition. I had originally named the drive "Storage 2".

When I go to "About This Mac" and then "System Report" the drive shows up as having the file system MS-DOS. It was previously exFAT like my other drive.

On Windows, that same drive says "F:\ is not accessible. The volume does not contain a recognized file system."

So my question is: How can I recover my drive which has mysteriously changed to MS-DOS format, and make it exFAT again?

I have attached a screenshot with all the info about the drive

 

[MacUser2525]

Never used the 10 but in any other version you would open a command prompt (DOS) window then run the chkdsk F: changing the F: if it was different to the drive letter that you want checked and possibly repaired file system errors on.

 

[casperes1996]

What happens if I eject?

Eject simply unmount the drive. Similar to command+e or dragging to the Trash which off course turns into an eject logo when dragging a drive, to make it safe to disconnect from the Mac.

Never used the 10 but in any other version you would open a command prompt (DOS) window then run the chkdsk F: changing the F: if it was different to the drive letter that you want checked and possibly repaired file system errors on.

Still works on Windows 10. Can also be done with the Mac Terminal, though for Dos or ExFAT drives you'd probably need another version of chk than the one Apple ships with. How much do you know about using the Terminal and Homebrew?

 

[boast]

What does diskutil info /dev/disk4 say?

Can you do a verify/repair on it?

diskutil verifyDisk /dev/disk4

 

[casperes1996]

What does diskutil info /dev/disk4 say?

Can you do a verify/repair on it?

diskutil verifyDisk /dev/disk4

Doesn't that only work with HFS+ volumes?

 

[boast]

Doesn't that only work with HFS+ volumes?

Not sure. I would assume verifyVolume is partition dependent, but I wouldn't think the disk itself should be.

 

[casperes1996]

Not sure. I would assume verifyVolume is partition dependent, but I wouldn't think the disk itself should be.

You're probably right on that actually

 

[tbjem0013]

What does diskutil info /dev/disk4 say?

Can you do a verify/repair on it?

diskutil verifyDisk /dev/disk4

[doublepost=1488076960][/doublepost]

What does diskutil info /dev/disk4 say?

Can you do a verify/repair on it?

diskutil verifyDisk /dev/disk4

 

[casperes1996]

[doublepost=1488076960][/doublepost]

Try doing this in Terminal -


sudo fsck_exfat -d disk0s4


replacing disk0s4 with your disk's identifier.

If it asks if it should restore boot regions or something like that, just say yes

 

[Fishrrman]

OP wrote:
"I use these drives with Windows 10 as well, so they are in exFAT.
When I go to "About This Mac" and then "System Report" the drive shows up as having the file system MS-DOS. It was previously exFAT like my other drive."

This is why I advise folks to never, never, NEVER, NEVER use a "cross-formatted" drive (i.e., fat or any Windows format) on which to store Mac files that are important to them.
Because, sometimes, inexplicably, one might connect that drive to a PC, then take it back to the Mac, and…. POOF! The files that "were there previously" are suddenly …. gone.

If you have Mac files that are important to you, keep them on a MAC-FORMATTED drive (i.e., HFS+) that NEVER TOUCHES a PC.

If you need to exchange files with a PC, use a dedicated cross-formatted drive or USB flashdrive for this purpose only.

Do you have backups?

 

[tbjem0013]

OP wrote:
"I use these drives with Windows 10 as well, so they are in exFAT.
When I go to "About This Mac" and then "System Report" the drive shows up as having the file system MS-DOS. It was previously exFAT like my other drive."

This is why I advise folks to never, never, NEVER, NEVER use a "cross-formatted" drive (i.e., fat or any Windows format) on which to store Mac files that are important to them.
Because, sometimes, inexplicably, one might connect that drive to a PC, then take it back to the Mac, and…. POOF! The files that "were there previously" are suddenly …. gone.

If you have Mac files that are important to you, keep them on a MAC-FORMATTED drive (i.e., HFS+) that NEVER TOUCHES a PC.

If you need to exchange files with a PC, use a dedicated cross-formatted drive or USB flashdrive for this purpose only.

Do you have backups?

Yes, I have backups. I have a second drive that's exactly the same where I also copy the same things to... most of the time. They aren't in a raid setup, I just copy stuff to both drives. I don't think I have anything important that hasn't been copied to both, so formatting this one wouldn't be that big of a deal. I just don't want to run into this issue again. You're right that I should make one of them a dedicated mac-formatted drive.
[doublepost=1488151663][/doublepost]

Try doing this in Terminal -


sudo fsck_exfat -d disk0s4


replacing disk0s4 with your disk's identifier.

If it asks if it should restore boot regions or something like that, just say yes

should I do this?

 

[casperes1996]

Didn't someone make a kext (is it also called that for NT?) for Windows so that you could both read and write HFS+ volumes on Windows? If so then that seems like the optimal solution
[doublepost=1488152977][/doublepost]

should I do this?

Yes, give it your password. It's necessary for it to do the operation on the disk, trying to save the partition. The warning you're seeing, is because "sudo" in the terminal, basically gives full access to whatever command comes after it. In this case, the full access is required to "file system check" (fsck) the disk.

 

[tbjem0013]

Didn't someone make a kext (is it also called that for NT?) for Windows so that you could both read and write HFS+ volumes on Windows? If so then that seems like the optimal solution
[doublepost=1488152977][/doublepost]

Yes, give it your password. It's necessary for it to do the operation on the disk, trying to save the partition. The warning you're seeing, is because "sudo" in the terminal, basically gives full access to whatever command comes after it. In this case, the full access is required to "file system check" (fsck) the disk.

It says it was repaired. I don't see the Storage2 volume in System Report or Disk Utility though.

 

[casperes1996]

It says it was repaired. I don't see the Storage2 volume in System Report or Disk Utility though.

From what that report said, here's what the command did, in a cartoony way of thinking.

"Wuhu! I get to repair an ExFAT file system! Let's have a look at this drive, shall we!"
"Hm.... I was told to repair en ExFAT partition, but there's 0 ExFAT data here... I guess I'll repair all the none existent files to comply with ExFAT."
"There! I did it. All the nothing is now repaired, and even though it's exactly the same as before because I didn't find anything to repair, having informed myself that there is no ExFAT data that I can see counts as a repair".

Since Mac OS claims it's a DOS/FAT partition, try
sudo fsck_MSDOS (disk identifier)
instead. It does the same thing, but for FAT32 partitions instead of ExFAT.
If that doesn't work either, I'm honestly clueless.

 

[tbjem0013]

From what that report said, here's what the command did, in a cartoony way of thinking.

"Wuhu! I get to repair an ExFAT file system! Let's have a look at this drive, shall we!"
"Hm.... I was told to repair en ExFAT partition, but there's 0 ExFAT data here... I guess I'll repair all the none existent files to comply with ExFAT."
"There! I did it. All the nothing is now repaired, and even though it's exactly the same as before because I didn't find anything to repair, having informed myself that there is no ExFAT data that I can see counts as a repair".

Since Mac OS claims it's a DOS/FAT partition, try
sudo fsck_MSDOS (disk identifier)
instead. It does the same thing, but for FAT32 partitions instead of ExFAT.
If that doesn't work either, I'm honestly clueless.

Didn't work. It's okay, I have pretty much everything backed up on my other drive. If I format it to HFS+ and then try copying all my files from my exFAT drive will it give me problems?

 

[casperes1996]

Didn't work. It's okay, I have pretty much everything backed up on my other drive. If I format it to HFS+ and then try copying all my files from my exFAT drive will it give me problems?

No.
The difference between file systems is how they store the files, not the files themselves. The location on the hardware itself will be different, but since you're not a software engineer writing apps like Finder, you won't have to deal with that. The system will know where data resides on ExFAT and where data is meant to reside on HFS+ and work it all out so the file is archived correctly under whichever file system it's placed in.

 

[tbjem0013]

No.
The difference between file systems is how they store the files, not the files themselves. The location on the hardware itself will be different, but since you're not a software engineer writing apps like Finder, you won't have to deal with that. The system will know where data resides on ExFAT and where data is meant to reside on HFS+ and work it all out so the file is archived correctly under whichever file system it's placed in.

Ok, thanks for all your help.