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ST2000DM001 Media won't mount

My iMac, purchased new from Apple in 2019, has been having significant problems since I installed the OS update in July. At the time, it crashed to a black screen with a white circle with a line through it. I got some help from Apple then and brought it back to life by starting in recovery mode, erasing the Macintosh HD disk, and starting fresh with a new OS download. All my data was backed up elsewhere, so that’s not an issue.


But since then, my 2TB storage has been missing. The drive ST200DM001 Media shows up in Disk Utility, but will not mount. I don’t have a great deal of computer savviness, but I think this is the root of my problem…something to do with a split fusion drive???


I recently tried erasing the Macintosh HD disk again, because it kept splitting itself into smaller and smaller bits labeled Macintosh HD - Data - Data - Data - Data - Data. Now I have a freshly reset Macintosh HD disk, a newly reinstalled OS (to the latest version available). And my iMac is still on the fritz. It keeps crashing and restarting, telling me on restart that the disk you attached was not readable by this computer. (No externals are attached...just the internal drives.)


First aid does nothing for either internal drive...comes up clean for both.


The error report on restart is attached. Relevant screen grabs are attached.




iMac 27″, macOS 12.1

Posted on Dec 18, 2021 3:30 PM

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Posted on Dec 18, 2021 4:22 PM

Also, I did try following Apple's split fusion drive directions yesterday in recover mode...specifically those copied/pasted below. I got an error of some kind. If you think it would be useful, I could go back into recovery mode, try again, and report the specifics.


If you're using macOS Mojave or later

  1. Turn on your Mac, then immediately press and hold Command-R to start up from macOS Recovery. Release the keys when you see the Apple logo or spinning globe.
  2. When you see the macOS Utilities window, choose Utilities > Terminal from the menu bar.
  3. Type diskutil resetFusion in the Terminal window, then press Return.
  4. Type Yes (with a capital Y) when prompted, then press Return.
  5. When Terminal indicates that the operation was successful, quit Terminal to return to the macOS Utilities window.
  6. Choose Reinstall macOS, then follow the onscreen instructions to reinstall the Mac operating system. Your Mac restarts from your Fusion Drive when done.



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Question marked as Best reply

Dec 18, 2021 4:22 PM in response to AlaskaBKO

Also, I did try following Apple's split fusion drive directions yesterday in recover mode...specifically those copied/pasted below. I got an error of some kind. If you think it would be useful, I could go back into recovery mode, try again, and report the specifics.


If you're using macOS Mojave or later

  1. Turn on your Mac, then immediately press and hold Command-R to start up from macOS Recovery. Release the keys when you see the Apple logo or spinning globe.
  2. When you see the macOS Utilities window, choose Utilities > Terminal from the menu bar.
  3. Type diskutil resetFusion in the Terminal window, then press Return.
  4. Type Yes (with a capital Y) when prompted, then press Return.
  5. When Terminal indicates that the operation was successful, quit Terminal to return to the macOS Utilities window.
  6. Choose Reinstall macOS, then follow the onscreen instructions to reinstall the Mac operating system. Your Mac restarts from your Fusion Drive when done.



Dec 18, 2021 11:26 PM in response to AlaskaBKO

It looks like something is definitely wrong with your hard drive. Between errors, no "S.M.A.R.T" status, and only showing 4.14GB when it should be 2TB.


Try to run First Aid on it: How to repair a Mac disk with Disk Utility - Apple Support, expand the window, and take a photo of the test results and upload it, like you did for the erase.


However, it looks like something with the hardware has failed, and you'll most likely need to visit an Apple Store for repair: Get Support.


Jack

Dec 18, 2021 4:15 PM in response to AlaskaBKO

Thanks for the quick suggestions, Jack. Disk utility won't let me erase the drive (see screen grab with error code). I downloaded Dx anyway and the report is attached. Also, just to check that I'm doing it right, when I clicked erase, I just made a new name and left the format and scheme drop downs where the defaults were (pic attached)

Dec 18, 2021 6:54 PM in response to Jack-19

I tried the steps. Error screen shot is below (sorry if it's turned sideways...it's vertical in my folder, but changes when I upload it). I also took a picture of the disk utility in recovery mode as it looked prior to the step in terminal.


After trying to fix the fusion drive in terminal by following the steps, I powered down from recovery mode and restarted in regular. But the computer wouldn't reboot. I went back into recovery and found out that the Macintosh HD drive had dismounted and changed its name to some letter/number combo I can't remember. That drive would not mount. I ended up erasing the Macintosh HD drive again and reinstalling the OS. And here I am again with the same disk problem.


Also note, I have no personal data on my computer at the moment (it's all stored elsewhere), so any drastic steps are a-ok.


Jan 7, 2022 4:37 PM in response to AlaskaBKO

I ran first aid on all four disks in recovery mode. The ST200DM001 just won't do anything. I'm afraid you're right about failed hardware. Unfortunately, I live overseas...distance and language barriers make visiting an Apple store very difficult. I think I will box this thing up and put it in the closet for another two years till I'm back State-side. That really sucks on a computer less than two years old, but I guess that's the way it is. Thanks for all your help confirming that it's something physical.

ST2000DM001 Media won't mount

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