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I have an external storage with 2TB that was working nicely. But since last week, when I unplugged the USB before eject it, the disk is not readable anymore.

When I insert USB, I can actually see this message box:

enter image description here

I also tried to repair it on Terminal:

diskutil unmountDisk force /dev/disk2
diskutil repairVolume /dev/disk2

That results on this error:

Error starting file system repair for disk2: Unrecognized file system (-69846)

Can anybody help me please?

EDIT

Terminal comand sudo gpt -r show /dev/disk returns:

gpt show: unable to open device '/dev/disk3': Resource busy

(even after umountDisk)

Terminal comand sudo fdisk /dev/disk returns:

Disk: /dev/disk3    geometry: 1003/16/63 [1011242 sectors]
Sector size: 4096 bytes
Signature: 0x0
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
 2: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
 3: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused
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7
  • 1
    What type of external storage, HDD or SSD and how was it formatted, HFS+? Have you tried plugging it in any other computer? Sounds like you corrupted the filesystem beyond repair by pulling the USB without properly ejecting it first.
    – user3439894
    Commented Dec 1, 2015 at 12:46
  • @user3439894 It's HDD. I guess that it was formated on Mac Os Journaling, but I am not sure! I already tested on another computer and same story - not readable. Is some way to repair file system?
    – fiskolin
    Commented Dec 1, 2015 at 12:49
  • It's going to depend on how damaged the filesystem on the drive is and the only suggestion I have is that if I was in this situation I'd try DiskWarrior if I really needed some files off of the drive. As a last resort, If you can live with loosing what's on the drive, you can always format it and put it back into service. Going forward, always maintain backups of files you do not want to loose.
    – user3439894
    Commented Dec 1, 2015 at 12:57
  • IMHO, if the file-system is munged there's not much mere mortals can do. You could try DiskWarrior or Stellar Volume Repair. As a last resort, you could contact DriveSavers Data Recovery. I used DiskWarrior for a client a few years ago and it was partially, but not completely, successful fixing the problem. Disclosure: I have no financial stake in any of the companies mentioned.
    – IconDaemon
    Commented Dec 1, 2015 at 13:05
  • @fiskolin Please unmount the disk and then enter sudo gpt -r show /dev/disk2 and sudo fdisk /dev/disk2 and add the results to your question.
    – klanomath
    Commented Dec 7, 2015 at 22:00

3 Answers 3

Reset to default
4

Try this in the exact order:

#FOR THE WHOLE DISK
diskutil eject /dev/disk2               #Eject the disk 
diskutil mountDisk /dev/disk2           #Re-mount the disk

#FOR THE VOLUME(S) OF THE DISK
diskutil list                           #list volume identifiers. 
diskutil mount /dev/disk2sXXX           #Mount the Volume. Dont enter a disk ID
diskutil repairVolume /dev/disk2sXXX    #Repair the Volume. Dont enter a disk ID

Basically you are trying to correct previous mounting/ejection related errors by making sure the disk is safely ejected before you do anything else.

Once that is out of the way, have the disk re-mounted. Next, have the volume re-mounted. Finally, repair the newly mounted volume.

Additionally, double check for any human error. Did you want to repair the volume or the disk because you specified a disk identifier to repair a volume. You typed:

diskutil repairVolume /dev/disk2

it should be

diskutil repairVolume /dev/disk2sXXX

Or use repairDisk if you wanted to repair a disk.

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2
  • I also noticed human error. You typed: diskutil repairVolume /dev/disk2 Did you want to repair the volume or the disk because you specified a disk identifier to repair a volume. It should be: diskutil repairVolume /dev/disk2sXXX Or use repairDisk if you wanted to repair the disk.
    – Trieu Nguyen
    Commented Dec 11, 2016 at 3:00
  • thank you so much man to made my day it surely save ton of $$$
    – Mudaser Ali
    Commented Aug 13, 2020 at 12:36
0

Probably a long shot now, but you could try to open terminal and run:

sync

Sometimes fixes problems when a disk is physically removed before files are written to the disk (or if files deleted from the disk are still in trash).

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-1

Just check the format. You probably have to format it correctly: GUID Partition Table, Mac OS Extended (journaled).

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