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  1. #1
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query

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    Disk Utilty first aid .. failed on external HDD MASTER BOOT RECORD query
    I have an external HDD ( 6TB ) that I ran Disk Utility first aid on. it failed.
    It ran ok on the VOLUME but when it ran on the DISK it failed.

    The drive looks different to others that I have as it shows that it is Mac OS Extended ( Journaled ) which is the same as other HDDs. However the partition map is showing as MASTER BOOT RECORD.

    All the other external disks that I have are Mac OS Extended (Journaled) with GUID partition map.

    Is it the different partition map ( Master Boot Record ) that is making the first aid fail?


    I am wondering if I format the disk with Mac OS Extended and GUID partition map and then copy the files back to it from another HDD using Carbon Copy Cloner will it then pass the first aid?
    The HDDs are kept for archival purpose mainly for photographic files.

    The error message gives a Disk Management error code which shows in the attached screenshot.

    Screen Shot 2020-06-01 at 7.55.10 pm.png



    Cheers


    Bernard
    Last edited by bernard smith; 06-01-2020 at 08:50 AM.

  2. #2
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query
    harryb2448's Avatar
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    Not good news for the drive I am afraid.
    Using OS X.7 or later make a bootable USB thumb drive before running Installer!

  3. #3
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query

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    A little confused right now. The suspect drive works on the Mac as files are copied to it from another HDD and the files can be then be opened on the mac using the suspect drive.

    What do you mean by not good news for the drive? Could you expand a little please.


    Cheers

    Bernard

  4. #4
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query
    krs's Avatar
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    Quote Originally Posted by bernard smith View Post
    I have an external HDD ( 6TB ) that I ran Disk Utility first aid on. it failed.
    It ran ok on the VOLUME but when it ran on the DISK it failed.

    The drive looks different to others that I have as it shows that it is Mac OS Extended ( Journaled ) which is the same as other HDDs. However the partition map is showing as MASTER BOOT RECORD.

    All the other external disks that I have are Mac OS Extended (Journaled) with GUID partition map.

    Is it the different partition map ( Master Boot Record ) that is making the first aid fail?
    I would think so.

    I'm not sure how you got to where you are....

    Did you format the drives originally?

    My understanding is that the Master Boot Record partition map only applies to MS-DOS & ExFat formatting;

    I would copy all the files from that volume showing as Master Boot Record to a temporary storage, then change the partition map to GUID and then copy the files back.

    But see what others have to say before doing anything.

  5. #5
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query

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    Thanks for your reply.. The drive was originally used on Windows PC then we changed to Mac.

    So I think that I had the disk in ExFat so that I could copy the files to a Mac OS Extended ( Journaled ) disk which had a GUID partition map.

    The "problem" disk was then changed from ExFat to Mac OS Extended ( Journaled ) but it looks like I didn't change the partition map to GUID at the time.


    As per your advice, I will sit a while and see what others say. I have two other external HDDs which are Mac OS Extended.. Journaled with GUID partition map and these have all the files in place and are copies of each other so no need to worry too much.


    Cheers

    Bernard
    Last edited by bernard smith; 06-01-2020 at 09:29 PM.

  6. #6
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query
    krs's Avatar
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    If you want the files on that drive to be accessible without any "helper apps" by both a Windows PC and a Mac, then the formatting should be ExFat and Master Boot Record. But there are some limitations that way on file naming etc. because of the ExFat formatting.

    If you only use that drive with a Mac, then the Mac OS Extended ( Journaled ) and GUID is the way to go.

    There are however third-party tools to read files on macOS formatted drives using a Windows PC if it ever comes to that.
    How to Read a Mac-Formatted Drive on a Windows PC

  7. #7
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query

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    The drive is only used on Mac , so I will format it Mac OS Extended (journaled) and this time make sure that the partition map is set to GUID. Then I will use Carbon Copy Cloner to copy files from another correctly set up drive. Hopefully after this has been done I will run DU first aid again and see if it works with the disk now having been set up for Mac properly.

    Cheers

    Bernard

  8. #8
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query
    krs's Avatar
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    Just a note:

    You only need to use Carbon Copy Cloner or SuperDuper or some other utility like that if you want to make a bootable backup of your active drive which includes your macOS.

    If you are just storing data (like images) which is what it sounds like from your first post, you can just copy them - ie drag and drop.
    If there are a lot, like in the thousands, it sometimes works better if you do them in lots rather than all at once.
    Not sure why, but I have had problems copying too many to an external drive at the same time - copying just stopped.
    The "workaound" was copying something like 500 images at a time.

  9. #9
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query

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    I use Time Machine which I believe makes a copy of the Mac OS along with other items such as Library, System. User, Desktop etc. anything that is on the internal Macintosh drive.

    The external drives are excluded from this Time Machine drive as they are just to big for the 1 TB time machine drive and that's why I have external HDD (6 TB) to keep the photographic files on. We are talking over 40,000 image files and associated xmp files etc.

    I am thinking that the Time Machine drive holds a "bootable" backup should I ever need it. It also holds my Lightroom catalog which is vital to me as it has years of adjustments to the photographic files within it.

    So I end up with 2 copies of everything that is on the internal Macintosh drive , one being the original on the Macintosh internal drive (1 TB SSD) as well as another duplicate on the 1 TB Time Machine SSD.


    Carbon Copy Cloner is used for the external HDDs because it only adds the incremental changes made to files in between the back ups and the files are being amended in some ways most days.

    I use CCC to make two additional copies of the main external HDD which is attached all the time. That way I end up with 3 copies of the photographic files as well as 2 copies of the internal Macintosh drive.

    It's just not feasible to drag and drop such large quantites and the Carbon Copy Cloner works really well.

    Thanks for all your time on this matter.


    Cheers

    Bernard
    Last edited by bernard smith; 06-02-2020 at 09:04 AM.

  10. #10
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query
    krs's Avatar
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    Based on your detailed explanation in what you are doing, I think you're right on the money the way you have things set up.

  11. #11
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query
    MacInWin's Avatar
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    One caution. The bootable TM only boots into recovery mode, from where you can reinstall the OS and then do the restoration. But if the drive fails, you have to replace the drive before you can boot and work on the drive systems.

    The clone drives, if you cloned the OS as well as the data, can boot and be used as the system drive while waiting for the replacement internal to come in. But if you have a failure if the internal drive, I would suggest that if you do decide to operate from a clone while waiting to replace the internal, that you only operate from ONE clone, and make it the same one each time, so that changes will be maintained for when you can install the new drive and clone back to the internal.
    Jake

  12. #12
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query
    Rod's Avatar
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    Beat me to it Jake.
    Don't be an April Fool: WORLD BACKUP DAY MARCH 31st

  13. #13
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query

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    Well, I felt brave today and reformatted the "poorly" HDD to Mac OS Extended ( Journaled ) with GUID partition map , instead of the MBR that it previously had.

    Then I used Carbon Copy Cloner to clone my photographic files from an existing HDD and presto!! I now have a fully functioning HDD that has also got a clean bill of health from Disk Utility First Aid.

    So now I have my main external HDD and two cloned copies ( by Carbon Copy Cloner ) and I also have my main Macintosh internal drive which is set up with Time Machine to a dedicated drive just for that purpose.

    Feel a bit more secure now..


    Thanks to everyone for all the advice and encouragement.

    Time for a brew now.


    Cheers


    Bernard

  14. #14
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query
    IWT's Avatar
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    Sounds brilliant, Bernard. Well done.

    Ian
    Ian

  15. #15
    Disk Utilty first aid .. failed on external HDD   MASTER BOOT RECORD query
    Rod's Avatar
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    Great to hear, well done you.


    Sent from my iPhone using Mac-Forums
    Don't be an April Fool: WORLD BACKUP DAY MARCH 31st

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