Mac Data Recovery

Solved: Mac Can’t Repair External Hard Drive

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    Summary: It could be nightmarish if you have got the below message through Disk Utility while repairing an external hard drive formatted with APFS or HFS. The purpose of this blog is to help you repair corrupt external hard drive on Mac. The blog shares three do-it-yourself methods to fix the drive and recover the data. Data recovery from corrupt external drive is feasible. Free download the software to self-evaluate.

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    Error: Disk Utility can’t repair this disk. Back up as many of your files as possible, reformat the disk and restore your backed-up files.

    The above message doesn’t show up in normal circumstances of external hard disk errors. In most cases, the Disk Utility is vigorous enough to repair an external drive and even your start-up disk. But if the external hard drive is beyond the repair scope of the Disk Utility, then it could be possible that the directory structure of the drive is corrupt severely.

    Don’t panic, the below 3 activities could be performed when Disk Utility fails to repair an external hard drive. Further, try Mac external hard drive recovery software as a last resort.

    1) Backup External Hard Drive Data

    You can try copy and paste all files from the corrupt external or internal hard drive to another destination. But doing this may also result in copying errors to another location. Moreover, the corruption may not allow you to copy & paste all the files from the disk.


    2) Fix Mac hard drive using FSCK

    You might have luck with FSCK command line.

    To run fsck command you have to restart Mac and log in as ADMIN. Launch Terminal, enter df -h1 and press Return. Use of df-h1 will let you know the path of the internal disk drive.

    Use below line

    sudo fsck_hfs -r -d /dev/disk1s1

    The command (-r) in the above code will recreate Catalog B – Tree. It will help you fix Invalid B-tree node problem occurred on the disk drive. It will further resolve errors like –

    • Invalid count
    • Invalid key length
    • Invalid volume file count
    • Invalid volume directory count
    • Invalid volume free block count, and likewise.

    3) Recover External Drive using Stellar Data Recovery Professional for Mac

    Though helpful, FSCK isn’t the sure shot method to repair the corrupt external/internal hard drive. You might need the help of a professional external hard drive recovery software for Mac. Stellar Data Recovery Professional is a sophisticated application to scan and recover your APFS or HFS drive.


    Step 1) Connect your external drive and launch Stellar Data Recovery Professional on your Mac. Customize your scan as shown below.


    Step 2) Select your external hard drive and toggle on Deep Scan feature. The deep scan feature scans all the sectors of the external hard drive to bring back lost data. Otherwise, stick with Quick Scan to recover the file-structure. Press the Scan button.

    Professional - Select the Location

    Step 3) After the external hard drive scans complete, navigate through the Classic list, File or Deleted List to view and preview your files.


    Step 4) If you have activated the Stellar Data Recovery Professional for Mac then you will be able to recover or save your files conveniently.

    Video Tutorial – Mac External Hard Drive Recovery


    Not just the corrupt HFS drive or volume but you can leverage & activate Stellar Data Recovery Professional for Mac to image an APFS external hard drive for the purpose of data recovery.

    The process to do the job will be the same as mentioned in the sequential steps and the video tutorial.

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    About The Author

    Vishal linkdin

    Vishal is a data recovery expert @Stellar. He addresses data loss scenarios on a Mac. He intends to help people solve their macOS problems. Besides, Vishal prefers to read about astronomy and autobiography, and his favorite is Steve Jobs - The man who thought different written by Karen Bluementhal.


    1. HI Vishal,
      Good day. I have a 2TB time capsule and we were using it to centrally store files, photos and videos.
      The Time capsule started failing and now we are not able to see the files any longer in finder.
      We proceeded to disassemble TC in order to remove the hard disk (seagate) and connect it directly to a MacBook Air (using SATA adapter). We are able to see the files directly in finder but it is not allowing us to back up or to copy the files to another external hard disk. (even more, the system is really slow)
      Would you recommend Stellar Volumen repair? The disk utility of the MacBook Air is showing messages that the hard disk is failing and cannot be repaired and that we should back up information as soon as possible.
      Thanks for your guidance.

      1. Hello Alex,

        I would like to inform that Stellar Volume Repair software is discontinued.

        Which Mac are you using right now? Are you getting any messages when you try to copy the files to another destination? I would recommend you to select the drive and press Command + I to get more info window. In this window, please check if you have permissions to read/write files on the mentioned drive. If permissions are set correctly then you can copy the files without any problem.

        Please let me know further.

    2. Hi.

      I have tried to repair a damaged APFS WD 4T external drive with fsck but always get the error of invalid key length (fsck_hfs -r -d /dev/disk4s2). This is a brand new HD!


      1. Hi Paul, Try using the command “sudo fsck_apfs -r -d /dev/disk4s2” then press Return. Provide the admin credentials to initiate the repair process. Thanks

    3. Hello,
      I had a hard drive crash due to physically damaged with vital files, which include video, documents, images, etc. Stellar Data Recovery is able to recover everything which I needed! But my hard drive physical condition was so bad. I reached your support team via call, and they recovered my whole data. I really thankful to you.

      1. Hello Fredric,
        We glad to know our technical support team helped you to recover your data from crashed hard drive.

    4. My SSD just died, for a couple of weeks I had typing issues and it started typing symbols, so I thought maybe it was the battery, removed it, worked fine for an hr or so, then back to same probs, eventually I was accessing from second Mac paired. then it just stopped working. As an external, I get : error 69874 operation failed …

      On disk Utilities I get : Size of Mass Storage Device media 11.4 TB !!!!!!!
      The SSD size is 600GB intel ssd dc s3500 !
      Media Info says Can not be verified, can not be repaired, not bootable, NO solid state, S.M.A.R.T. status NOT supported .

      Is there any hope in recovering data, really important documents on desktop and some 550GB of audio and video ……

      1. We recommend to use Stellar Volume Repair software to repair the hard drive because it is a case of corrupted Hard drive. Our software is compatible with Mac OS Sierra 10.12, 10.11, 10.10, 10.9, 10.8, 10.7 and 10.6.

        Kindly try the demo version of Stellar Volume Repair from the below link:

        [DMG Removed since Stellar Volume Repair is discontinued] Read More

        If you face any issue regarding the functionality of any of our software then please write an email to support[@]

    5. I want to know how to fix APFS Volume Invalid error on Mac OS High Sierra and how to recover data from this APFS drive?

      1. If your files are lost from APFS drive, you need to perform data recovery on this drive and later reformat the drive to fix this issue. In case your files are still there in the drive, just take the backup of your data and reformat the drive.

    6. Hello, I am trying out Stellar Volume Repair for and external USB drive (Seagate 3TB).
      When the application opens it showed both my external drives with just the icon and no other information. To make sure I did not affect the other volume I first ejected the good volume and then unplugged it. I then selected the remaining icon. The applicaiton immediately disappeared. I restarted it and the problem disk no longer showed up. So I unplugged the bad drive and plugged it back in, then restarted the application. Same thing happened again.

      1. Please let us know the following details in order to analyze your issue:

        1. Reason for corruption
        2. Version of Mac installed.
        3. Size of the Hard Drive.
        4. What is the file system of the drive/partition?
        5. Screenshot of Disk Utility displaying the Hard Drive.

        Hoping for your kind cooperation.

    7. Hello TJ,

      Thank you for contacting Stellar Data Recovery

      As you have two MacBook Pro machine and both have Mac OSX 10.9 Mavericks so you can create a bootable USB from your working Mac machine.

      Once you have successfully created a bootable USB then you can use it to boot your non-working Mac and to repair the volume.

      Please feel free to get back to us for any further query.

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