Trying to format hard drive difficulties

Discussion in 'Mac Pro' started by FyerFyer, Apr 2, 2016.

  1. FyerFyer macrumors regular

    FyerFyer

    Joined:
    Dec 14, 2015
    #1
    Hey guys

    I'm trying to format my hard drive on my Mac Pro but I keep getting error "couldn't unmount disk".

    Can anyone help?

    I'll attach a file of terminal in post below
    --- Post Merged, Apr 2, 2016 ---
    Here is my terminal list:
    (Couldn't upload pic)

    0 GUID PARTITION SCHEME disk0
    1 EFI EFI disk0s1
    2 Apple_HPS disk0s2
    3 Apple_Boot disk0s3
     

    Attached Files:

  2. monkeybagel macrumors 65816

    Joined:
    Jul 24, 2011
    Location:
    United States
    #2
    I am assuming you booted from the Recovery HD instead of a USB flash drive? If so, you can't format the entire disk because the Recovery HD is running from the disk you are trying to format. Try clicking Macintosh HD and click Erase.
     
  3. rigormortis macrumors 68000

    rigormortis

    Joined:
    Jun 11, 2009
    #3
    you must boot from recovery mode to format your hard disk. you either hold down command r ( or option command r) doing boot, or you boot from an os x installer that you wrote on a sd card. you can't format a hard disk that you booted from
     
  4. monkeybagel macrumors 65816

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    United States
    #4
    Option-Command-R will not work on any Mac Pro earlier than the 6,1 as none of the old ones have an EFI that is Internet Recovery bootable.
     
  5. FyerFyer thread starter macrumors regular

    FyerFyer

    Joined:
    Dec 14, 2015
    #5

    Hey guys
    Thanks for your replies.

    I'm a little bit confused

    I'm formatting the drive because I'm selling the computer. If recovery HD is formatted does that mean someone can recover my stuff..?
     
  6. monkeybagel macrumors 65816

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    United States
    #6
    What version of OS X is on it?
     
  7. rigormortis macrumors 68000

    rigormortis

    Joined:
    Jun 11, 2009
    #7
    back up to time machine first


    there are two ways to secure your computer.

    1) if your computer has a mechanical old school hard drive click on secure erase and set it to do more then 3 full passes

    2) if your computer has a SSD hard disk drive, turn on file vault, wait for the entire disk to encrypt, then do a full pass erase once


    once the hard disk is erased, reset your pram

    http://thenextweb.com/lifehacks/2010/12/04/how-when-why-to-reset-the-pram-smc-on-your-mac/#gref


    once the hard disk is erased, you should be okay. if you want you can do the next owner a favor and install os x for them

    i found out the pram contains the last wifi network's password you connected to, so if you are ultra paranoid, its a good idea to clear the pram
     
  8. FyerFyer thread starter macrumors regular

    FyerFyer

    Joined:
    Dec 14, 2015
    #8
    Thanks for your reply

    I've backed up everything into my ext hd but I'm still confused about my previous posts. Can anyone advise on these? If I only format Macintosh HD will the new user be able to restore my stuff..?
     
  9. Gjwilly macrumors 68030

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    May 1, 2011
    Location:
    SF Bay Area
    #9
  10. monkeybagel macrumors 65816

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    #10
    If you want to make sure that the drive is 100% clean, you can do so by making a bootable OS X install volume on a USB flash drive. There are many guides on how to do this. Booting from the flash drive will allow you to securely erase the entire HDD and reinstall OS X. Select the 3-pass option when erasing, which will take several hours.
     
  11. FyerFyer thread starter macrumors regular

    FyerFyer

    Joined:
    Dec 14, 2015
    #11
    Thanks guys

    I'm gonna try and erase the Macintosh HD and see what happens
     
  12. FyerFyer, Apr 3, 2016
    Last edited: Apr 3, 2016

    FyerFyer thread starter macrumors regular

    FyerFyer

    Joined:
    Dec 14, 2015
    #12
    So I've successfully formatted the drive but it still says there is 613 mb used in 3 files..?

    However the real issue now is trying to reinstall the software. I hv the original disk but it says "Mac OS X cannot be installed on this machine"aghhh

    Can anyone help..?
     
  13. Gjwilly macrumors 68030

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    May 1, 2011
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    SF Bay Area
    #13
    Which Mac? Which OS X did it used to have? And which OS X is your installer? Also, where did you get the installer?
     
  14. FyerFyer thread starter macrumors regular

    FyerFyer

    Joined:
    Dec 14, 2015
    #14
    It's a Mac Pro 5.1 I think. The OS X I tried to install from a cd was snow leopard. The disk came with it.

    I have downloaded a dmg of snow leopard onto my windows comp as another option. Is it possible to make an OS X usb bootdisk from a Windows computer..?
     
  15. h9826790 macrumors 604

    h9826790

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    Apr 3, 2014
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    Hong Kong
    #15
    If you have the original disc, why don't you just boot from the disc and format HDD / install OSX from there?
     
  16. FyerFyer thread starter macrumors regular

    FyerFyer

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    Dec 14, 2015
    #16
    I tried that but it wouldn't allow it.

    Atm the drive is formatted but cannot install from cd
     
  17. h9826790 macrumors 604

    h9826790

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    Hong Kong
    #17
    The recovery disc wouldn't allow you to install the OS?
     
  18. FyerFyer thread starter macrumors regular

    FyerFyer

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    Dec 14, 2015
    #18
    If the recovery disk is the cd then yes it won't allow it.
     
  19. h9826790 macrumors 604

    h9826790

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    Hong Kong
    #19
    Yes, I am talking about that CD.

    So, when you boot from the disc, you can format the HDD, but can't install OS, what't the error message?

    P.S. I know that your HDD is now formatted, but seems not 100%. That may be the issue. Why not try to format the whole HDD again (if you can do that via the disc).
     
  20. FyerFyer thread starter macrumors regular

    FyerFyer

    Joined:
    Dec 14, 2015
    #20
    I erased the disk through the "cmd r" at startup.

    The cd has never been used. The cd just won't work when I boot from it. All it says is "cannot install OS X on this machine"
     
  21. h9826790 macrumors 604

    h9826790

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    Apr 3, 2014
    Location:
    Hong Kong
    #21
    I didn't use that disc for a long time. But from memory, that disc should work like the recovery partition (CMD R). So, you can format the whole HDD at there.

    In fact, the recovery partition is a part of the HDD. If you boot from that, you can format the OSX partition, but not the entire HDD.

    Did you actually try to format the entire HDD again when you boot from the disc? If not, please do that.
     
  22. CapnDavey macrumors 6502

    CapnDavey

    Joined:
    Apr 11, 2015
    #22
    thats the issue the 10.6 OS is to old to go into a 5.1 they were made in 2010 did you try Lion? it might work
     
  23. r6mile macrumors 6502

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    Feb 3, 2010
    Location:
    London, UK
    #23
    Do you have a USB drive with at least 8GB? You can just make a bootable El Capitan partition, and boot into that to totally erase the hard drive.
     
  24. h9826790, Apr 4, 2016
    Last edited: Apr 4, 2016

    h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #24
    OP said that's the disc came with his Mac Pro.

    My understanding is that's the recovery disc, not the snow leopard retail disc. That disc may came with 10.6.x which works on the 5,1, but not 10.6.0 which not support the 5,1.

    Unless his Mac is a 4,1 flashed to 5,1. The disc should work.

    Of course, may be I am totally wrong. In that case, I agree that the 10.6 disc won't work on a 5,1.

    If OP can post the picture of the disc, that will make us much easier to give out proper suggestion.
     
  25. FyerFyer thread starter macrumors regular

    FyerFyer

    Joined:
    Dec 14, 2015
    #25
    Thanks

    But when I boot from the cd there is no option except installation.

    I choose the language then it just says "Mac OS X can't be installed on this computer

    The only way for me to format is through the disk utility menu
    --- Post Merged, Apr 4, 2016 ---
    Ahhh ok I'll try that then. I'll try mountain lion or El Capitan
    --- Post Merged, Apr 4, 2016 ---
    Can I make a bootable from a Windows machine as my Mac at home doesn't hv internet..?
     

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