User profile for user: EverythingZen
EverythingZen Author
User level: Level 1
3 points

How To Rebuild Missing 'Macintosh HD' Drive?

Hello


Computer: Late 2013 iMac 27" Fusion Drive

Note: My files are backed-up and safe via Time Machine


The Problem:

As viewed in Disc Utilities ... The second drive: 'Macintosh HD' is not recognised (does not appear at all).

Steps Leading Up To The Problem:

  • I attempted to clean install Yosemite.
  • I booted from a flash drive with the Yosemite OS X Installer on it.
  • I attempted to erase the second sub-drive 'Macintosh HD' ... 'Securely'.
  • Upon seeing that a 'Secure' erase would take 3 hours ... I decided to 'Skip' this and perform a quick standard erase.
  • After pressing 'Skip' ... 'Macintosh HD' turned grey.
  • I attempted a standard erase ... But Disc Utilities stated 'Macintosh HD' needed to be repaired.
  • However, the repair button was greyed out ...
  • So I attempted to repair the first drive (which is also called 'Macintosh HD' on my system).
  • This was 'Verified' and 'Repaired' with no problems ...
  • But the second sub-drive (that I attempted to erase) ... 'Macintosh HD' ... Disappeared.


So I no longer have a recognisable drive to install a fresh OS X onto ... Or even to do a Time Machine restore onto.

Obviously interrupting the secure erase process deleted something important and made 'Macintosh HD' unrecognisable.


What I have tried:

  • Creating a new partition by clicking on the 'Partition' tab with the first drive selected ... But all the options are grey.
  • Booting into single user mode and typing 'fsk -fy' ... This confirmed the initial drive was fine but did nothing to fix the situation.


My Question:

  • Can I recreate the missing 'Macintosh HD' drive myself? ... If so ... How?
  • Or will this require an Apple technician?


Please note, I am not concerned about loosing data.

I just want a fresh and stable, factory restored computer.


Thanks in advance for any help.

iMac, iOS 8.1.2

Posted on Dec 25, 2014 1:10 AM

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5 replies
User profile for user: EverythingZen
EverythingZen Author
User level: Level 1
3 points

Dec 25, 2014 5:20 AM in response to EverythingZen

I solved this problem myself after more forum searching


For those who encounter the same problem ... I read this thread:

http://apple.stackexchange.com/questions/59026/how-to-install-mountain-lion-on-a -disk-that-cannot-be-formatted-in-recovery-mode


The steps I took:

  • I booted from recovery mode (Hold 'Command' and 'R' while starting up)
  • From the menu screen ... On the top bar I selected 'Utilities > Terminal'.
  • This opened a terminal window.
  • Then I typed: diskutil CoreStorage list
  • And hit 'Return' ...
  • This showed the main storage drive details.
  • From there I found the UUID string ...
  • Which is basically the long number displayed under the storage drive name.
  • I selected and copied this ...
  • Then I typed: diskutil CoreStorage delete
  • Followed by the UUID string number ... And hit 'Return'.
  • The system then erased the main drive (it left the recovery dive intact though).
  • I then quit Terminal ... And went back into 'Disc Utilities'.
  • Only to find all of the drives displayed individually and in red ...
  • The 'Solid State Drive' and the 'Hard Disc Drive' were no longer displayed as one 'Fusion' unit.
  • However ... Upon clicking on one of the drives ...
  • The system recognised they were not unified ... And prompted me to fix this.
  • I asked the Disk Utilities to 'Fix' ... And the system returned to its normal state.
  • With the drives displayed as:

• Internal Drive

• Macintosh HD

I was then able to install the OS X on the 'Macintosh HD' partition.

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User profile for user: cyberneticghost
cyberneticghost
User level: Level 1
12 points

Jul 26, 2017 10:35 AM in response to EverythingZen

Extremely helpful. I had the exact same problem except I didn't skip the secure erase, it just had an error during secure erase which interrupted it. Then the machine suddenly became very sluggish and even unresponsive. I tried a clean install, somehow made it worse. I followed every single step you listed, now everything is working perfectly again. ✅


Thanks very much.

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How To Rebuild Missing 'Macintosh HD' Drive?

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