Macintosh HD erased by Disk Utility in recovery mode

Discussion in 'OS X El Capitan (10.11)' started by sebman28, Dec 4, 2015.

  1. sebman28 macrumors newbie

    Joined:
    Dec 4, 2015
    #1
    New 27" Mac, was going to reinstall El Capitan. Followed these instructions : https://support.apple.com/kb/PH21973?locale=en_US&viewlocale=en_US

    Now in Disk Utility the indented Macintosh HD drive is missing. When I go in to reinstall the OS X ,Macintosh HD is missing.

    I tried starting in about every mode with no success. With a tech at apple for an hour couldn't figure it out and said I needed to bring it in. Seems strange that there isn't anything I can do.

    I have an appointment at the apple store but I thought I'd see if anyone had advice so I could forego the appointment.

    Thanks in advance for any help!
     
  2. keysofanxiety macrumors 604

    keysofanxiety

    Joined:
    Nov 23, 2011
    #2
    So just to confirm, nothing shows up in Disk Utility? Or is it just the indented volume that isn't visible?

    Because you could try clicking the master HDD and then selecting Erase which should then create a new volume, and it'll be back. What happens when you try to do that?
     
  3. sebman28 thread starter macrumors newbie

    Joined:
    Dec 4, 2015
    #3
    Fusion drive shows up nut not the indented Macintosh HD. The recovery disk is there. Clicking on the Fusion drive and trying to partition or first aid do not work.
     
  4. Fishrrman macrumors G4

    Fishrrman

    Joined:
    Feb 20, 2009
    #4
    If you get nowhere, take it to the nearest Apple Store -- it's still under warranty.
     
  5. Weaselboy, Dec 4, 2015
    Last edited: Dec 4, 2015

    Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #5
    It sounds like you inadvertently separated the Fusion drive. Try this...

    Hold command-option-r to boot to Internet recovery. Once you choose your wifi you will see a spinning globe while the recovery utility loads. Once that is done you will see the recovery screen. Click in the utilities menu up top and select Terminal. Type in the line below exactly like I have it including the quotes and hit return. That will kill the Fusion drive.

    Code:
    diskutil cs delete "Macintosh HD"
    Now quit Terminal and launch Disk Utility. It should look like this and offer to fix the Fusion drive. Go ahead and tell it to fix it and it will combine the two drives and format.

    Then quit Disk Utility and click reinstall OS X.

    fusion_drive_disk_error.png
     
  6. sebman28 thread starter macrumors newbie

    Joined:
    Dec 4, 2015
    #6
    Weaselboy, I believe you were on the right track. I had my appointment at the Apple Store today and the first thing he did when it would only start in recovery mode was go to the terminal. It didn't take him long so I'm assuming he probably typed in what you mentioned there and then the disc was created then they want to head and installed OS X.

    I'm doing the user set up right now transferring data so I'm hoping that this is the end of it reply to this post and let you know the outcome.

    Thank you all for replying!!! this with my second iMac in a month! My first had a motherboard issue so you can imagine my frustration.
     
  7. Donfor39 macrumors 6502a

    Donfor39

    Joined:
    Jul 26, 2012
    Location:
    Lanarkshire Scotland
    #7
    This is interesting, what caused the missing mac hd, fusion drive separates? -thats new to me how does that happen
     
  8. sebman28 thread starter macrumors newbie

    Joined:
    Dec 4, 2015
    #8
    I'm still not sure what caused it. The apple tech gave me his # so I'm going to call him for further explanation just in case I need to do it again.

    The strange thing is that when set-up finished in Disk Utility there are now two Internal Macintosh HD drives?
    • APPLE HDD ST2000DM001>Macintosh HD - Fusion Drive 2 TB capacity - This is the start up drive where the OS and everything else is loaded properly.
    • APPLE SSD SM0128G>Macintosh HD II (renamed since both were "Macintosh HD") 120.99 capacity
    I'm guessing that my Fusion Drive was De-Fused?
    Should I be worried about the SSD showing up under Internal and not Disk Images?
     
  9. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #9
    Run the two commands below in Terminal one after the other and tell us the output of both. Also post up a screenshot of Disk Utility.

    Code:
    diskutil list
    
    diskutil cs list
     
  10. sebman28 thread starter macrumors newbie

    Joined:
    Dec 4, 2015
    #10
    iMac:~ sebman$ diskutil list

    /dev/disk0 (internal, physical):

    #: TYPE NAME SIZE IDENTIFIER

    0: GUID_partition_scheme *2.0 TB disk0

    1: EFI EFI 209.7 MB disk0s1

    2: Apple_HFS Macintosh HD 2.0 TB disk0s2

    3: Apple_Boot Recovery HD 650.0 MB disk0s3

    /dev/disk1 (internal, physical):

    #: TYPE NAME SIZE IDENTIFIER

    0: GUID_partition_scheme *121.3 GB disk1

    1: EFI EFI 209.7 MB disk1s1

    2: Apple_HFS Macintosh HD II 121.0 GB disk1s2

    iMac:~ sebman$ diskutil cs list

    No CoreStorage logical volume groups found

    iMac:~ sebman$
    http://postimg.org/image/s7nxjqub9/

    http://postimg.org/image/b45k12xp5/
     
  11. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #11
    Yeesh.... well obviously the Apple tech had no clue what they were doing. You do not have a Fusion drive setup. You have the 2TB hard drive with the OS and everything else installed on it, then the SSD sitting there empty and unused.

    Go back to a command-option-r boot to Internet recovery and once you get past the globe and to the recovery screen, try to start Disk Utility and see if it offers to fix the Fusion drive like I described earlier. If it does not... just quit Disk Util and from that same recovery screen launch Terminal from the Utilities menu then enter the commands below one after the other.

    Code:
    diskutil cs createLVG "LVG-1" /dev/disk0 /dev/disk1
    
    diskutil cs createLV "LVG-1" HFS+J "Macintosh HD" 100%
    That should create the Fusion drive. Then you can reinstall the OS from recovery. To verify run "diskutil cs list" for me again. The output should look like the one below here, except your Macintosh HD at the top will be 2.1TB.

    Code:
    xxx-Mac-mini:~ xxx$ diskutil cs list
        CoreStorage logical volume groups (1 found)
        |
        +-- Logical Volume Group 31CBA650-4ABC-4DA6-AA73-6D96B36693E2
            =====================================================
            Name:         Macintosh HD
            Size:         1120333979648 B (1.1 TB)
            Free Space:   0 B (0 B)
            |
            +-< Physical Volume F4A50F9C-841D-4C6D-AFC4-6A10560E0717
            |   ----------------------------------------------------
            |   Index:    0
            |   Disk:     disk0s2
            |   Status:   Online
            |   Size:     120988852224 B (121.0 GB)
            |
            +-< Physical Volume C86789FD-1978-453A-BCA7-81DC05AA66C7
            |   ----------------------------------------------------
            |   Index:    1
            |   Disk:     disk1s2
            |   Status:   Online
            |   Size:     999345127424 B (999.3 GB)
            |
            +-> Logical Volume Family AA92FDF8-F962-4DE3-AC2F-1B6ABF22AA22
                ------------------------------------------------------
                Encryption Status:       Unlocked
                Encryption Type:         None
                Conversion Status:       NoConversion
                Conversion Direction:    -none-
                Has Encrypted Extents:   No
                Fully Secure:            No
                Passphrase Required:     No
                |
                +-> Logical Volume B97C9558-14FC-4BFC-B413-AFB292BD29F0
                    -----------------------------------------------
                    Disk:               disk2
                    Status:             Online
                    Size (Total):       1115853029376 B (1.1 TB)
                    Size (Converted):   -none-
                    Revertible:         No
                    LV Name:            Macintosh HD
                    Volume Name:        Macintosh HD
                    Content Hint:       Apple_HFS
    Of course, make sure you are backed up because this will wipe the drives.
     
  12. sebman28 thread starter macrumors newbie

    Joined:
    Dec 4, 2015
    #12
    OMG! You are a lifesaver!!! I try this later today and ket you know.
     
  13. MelisaFilm macrumors newbie

    MelisaFilm

    Joined:
    Nov 10, 2016
    #13
     
  14. HaraldB macrumors newbie

    Joined:
    Dec 2, 2017
    Location:
    Norway
    #14
    I was really stuck when "Machintosh HD" was lost and not visible in Disc Utility (in recovery mode). I could see discs in "diskutil list" but nothing helped. I've scanned site after site for a solution, but couldn't find it befor I found your code.

    Code:
    diskutil cs createLVG "LVG-1" /dev/disk0 /dev/disk1
    
    diskutil cs createLV "LVG-1" HFS+J "Macintosh HD" 100%
    It gave a error running it. But somehow it made my disk visible in Disk Utility again!!!

    I could then partition the "untitle" to a new "Macintosh HD" and finally reinstall OS.
     

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