Damaged Fusion Drive is missing a disk - Can I Rebuild the MBR?

Discussion in 'iMac' started by speedjohnson, Jan 21, 2016.

  1. speedjohnson, Jan 21, 2016
    Last edited: Jan 21, 2016

    speedjohnson macrumors newbie

    speedjohnson

    Joined:
    Jan 21, 2016
    #1
    Hey there,

    Long time lurker so first wanna say thanks for all the help over the years.

    (Edit - it seems I need to somehow repair the permission table)

    Here's my trouble:

    Today I tried to reinstall Windows using bootcamp on my 1TB fusion drive.

    I was getting the error message that windows could not be installed because " The selected disk has an MBR partition table. On EFI systems, Windows can only be installed on GPT disks. "

    After trying some different suggestions I tried this one:



    Which showed me how to convert the MBR to a GPT using MS DOS during the windows installation.

    Oh dear.

    My Mac now no longer recognises the fusion drive (circle with line through it) and I get this message in disk utility:



    [​IMG]



    [​IMG]



    I'd be happy to format and start again but stupidly didn't back up my Mac hard drive before fiddling around, would like to know if there is anyway of rebuilding the MBR / fixing the fusion drive without formatting?


    THere's this cool little program http://www.partitionwizard.com/help/rebuild-mbr.html but not sure if there's a way to open during the windows installation - it obviously wont open with the mac.

    Any help would be much appreciated!

    Cheers in advance ;)
    Adam


    iMac (Retina 5K, 27-inch, Late 2014), Mac OS X (10.7.5), null
     
  2. speedjohnson thread starter macrumors newbie

    speedjohnson

    Joined:
    Jan 21, 2016
    #2
    Edit:


    It seems I need to repair the partition table, but can't seem to find how to do this...



    Also it seems the two partions within the overall Fusion drive are ok - its the "overall" Internal Drive that is show "Offline"



    -bash-3.2# diskutil corestorage list

    CoreStorage logical volume groups (1 found)

    |

    +-- Logical Volume Group AC79ACAF-A36B-4F07-BB9A-9CF92DF796BD

    =========================================================

    Name: Internal Drive

    Status: Offline

    Size: 862577819648 B (862.6 GB)

    Free Space: -none-

    |

    +-< Physical Volume 909F3B47-0438-40C3-9DF2-C970AF02FE75

    | ----------------------------------------------------

    | (No properties)

    |

    +-< Physical Volume 350EB3CD-6DBD-4D9D-9A27-DD611299AF24

    ----------------------------------------------------

    Index: 1

    Disk: disk1s2

    Status: Checking

    Size: 862577819648 B (862.6 GB)

    -bash-3.2# sudo diskutil list

    -bash: sudo: command not found

    -bash-3.2# diskutil list

    /dev/disk0

    #: TYPE NAME SIZE IDENTIFIER

    0: *121.3 GB disk0

    /dev/disk1

    #: TYPE NAME SIZE IDENTIFIER

    0: GUID_partition_scheme *1.0 TB disk1

    1: EFI EFI 209.7 MB disk1s1

    2: Apple_CoreStorage 862.6 GB disk1s2

    3: Apple_Boot Boot OS X 134.2 MB disk1s3

    4: Microsoft Basic Data 130.0 GB disk1s4

    5: Apple_HFS Untitled 7.0 GB disk1s5

    /dev/disk2

    #: TYPE NAME SIZE IDENTIFIER

    0: Apple_partition_scheme *1.3 GB disk2

    1: Apple_partition_map 30.7 KB disk2s1

    2: Apple_HFS OS X Base System 1.3 GB disk2s2

    /dev/disk3

    #: TYPE NAME SIZE IDENTIFIER

    0: FDisk_partition_scheme *32.1 GB disk3

    1: Windows_FAT_32 CANON 32.1 GB disk3s1

    /dev/disk4

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *5.2 MB disk4

    /dev/disk5

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *524.3 KB disk5

    /dev/disk6

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *524.3 KB disk6

    /dev/disk7

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *524.3 KB disk7

    /dev/disk8

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *524.3 KB disk8

    /dev/disk9

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *524.3 KB disk9

    /dev/disk10

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *6.3 MB disk10

    /dev/disk11

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *2.1 MB disk11

    /dev/disk12

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *1.0 MB disk12

    /dev/disk13

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *524.3 KB disk13

    /dev/disk14

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *524.3 KB disk14

    /dev/disk15

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *1.0 MB disk15

    /dev/disk16

    #: TYPE NAME SIZE IDENTIFIER

    0: untitled *6.3 MB disk16

    /dev/disk17

    #: TYPE NAME SIZE IDENTIFIER

    0: GUID_partition_scheme *3.0 TB disk17

    1: EFI EFI 209.7 MB disk17s1

    2: Apple_HFS M' Drive VI 3.0 TB disk17s2

    -bash-3.2#









    Any ideas?
     
  3. dimme macrumors 65816

    Joined:
    Feb 14, 2007
    Location:
    SF, CA
  4. speedjohnson thread starter macrumors newbie

    speedjohnson

    Joined:
    Jan 21, 2016
    #4
    Thanks for the tip,

    I tried that late last night but seems I'm having problems making a bootable drive on the mac - tried using Unetbootin but says "this will not boot from a mac, use a PC",

    Do you have any tips on how to mac a GParted bootable USB on the Mac - all the advice and alternative programs I can find seem to be PC based.

    Thanks for your help :)
     
  5. giffut, Jan 22, 2016
    Last edited: Jan 22, 2016

    giffut macrumors 6502

    Joined:
    Apr 28, 2003
    Location:
    Germany
    #5
    Sorry to say, but I think you are out of luck here. Your windows/dos boot partition conversion destroyed the block level based fusion drive organization. There is not much information available about the underlying principles of a fusion drive and I know of no repair program to do so.

    Take it for lessons and never ever do NOT backup a dual drive setup, where the failure rate doubles compared to a single drive system. Or basically: Without one backup at least consider any drive lost already.
     
  6. speedjohnson thread starter macrumors newbie

    speedjohnson

    Joined:
    Jan 21, 2016
    #6
    No worries, thanks for your reply - it does look fairly impossible doesn't it.

    Rather than restoring a working drive - do you think there would be any hope for scanning for lost files after the format? Or is do you think this carnage will have caused too much damage?
     
  7. giffut macrumors 6502

    Joined:
    Apr 28, 2003
    Location:
    Germany
    #7
  8. speedjohnson thread starter macrumors newbie

    speedjohnson

    Joined:
    Jan 21, 2016
    #8
    I used DiskDrill in the end, managed to rescue most of it in the end (DiskWarrior didn't recognise it at all)

    This is a great video for rebuilding a Fusion drive once you're ready to reformat and wipe the slate clean:

     

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