User profile for user: Breezez
Breezez Author
User level: Level 1
8 points

Fusion Drive Issue - Need to Upgrade

Hello,


I have a late model 2012, 27” iMac with a fusion hard drive. It’s been giving me fits for last couple weeks. It sometimes boots up, and once booted it acts real sluggish and the the circular wheel before system crashes after a few minutes. I tried recovery mode first time I saw both my 128GB drive and my 3.2TB drive separate both red in utility window. I do not try to fix them, as it said it would erase everything. I reboot and still sometimes never boot all way before crashing but other times would boot then a few minutes later would crash. I tried safe mode. After 3 attempts I was able to move some of my files to icloud, but then crashes again. Now it doesn’t seem to even want to boot up in safe mode, recovery mode works only now I only see the blade drive 128GB drive on motherboard.


No I don’t have a TM backup of my data, know that sucks but most of my stuff was on iCloud. I guess what was not on there I will have to accept the loss.


So my question is on upgrading. I watched several videos today on opening unit. But here is what I’m not sure about I would like your help with.


1) Do I need to use the terminal window undo the fusion drive link if drive is not working? If so what command(s) do I enter.


2) It looks like 128GB drive is fine. Is it worth effort to increase its size too. Or is the additional risk of pulling logic board out weight the benefit? Recovery mode is showing this drive with no errors.


3) I was planning on ordering the Samsung EVO 870 2TB drive. And the OWC SATA temp sensor module. Would you recommend setting this up as a standalone drive or as a fusion drive paired with the 128GB logic board mounted drive?


4) I am assuming my recover partition was on 3.2GB drive in computer that appears to have failed. So how do I reinstall OS, I was running Latest OS as of 30 days ago.


5) what are the steps I have to follow to set new drive up like partitioning it?


6)Finally is there any thing special I need to do to ensure SSD behaves correctly in the make like TRIM working?


Thanks in advance for your help


Posted on Mar 20, 2021 11:59 AM

Reply

Similar questions

4 replies
User profile for user: rkaufmann87
rkaufmann87
User level: Level 10
148,488 points

Mar 20, 2021 12:11 PM in response to Breezez

DO NOT attempt to open and repair the computer yourself. What most experienced users on these forums will counsel you to do is to get an external SSD (USB 3 or 3.1) and connect that to the iMac. The is the fastest, least risky and easiest method!!!!! Once you have the SSD, please restart in the Recovery Partition if you can (hold down Command + R on startup until it launches) and then use the utility to install Mac OS on the new SSD and then restart to the SSD (hold down option key on start and select the SSD and you are in business. Then set the SSD in System Preferences as your startup disk and you done! Below is what I'd recommend that you use.


https://eshop.macsales.com/shop/firewire/on-the-go and a

https://eshop.macsales.com/item/OWC/MOTGPWR/



Reply
User profile for user: Jack-19
Jack-19
User level: Level 8
46,188 points

Mar 20, 2021 12:34 PM in response to Breezez

Hi there,


Use an external USB SSD and run macOS off that that. If you want to proceed with this, I recommend the: https://eshop.macsales.com/item/OWC/ENVPK01/?fullDetails. 


If you get it, below is how to set it up as your startup disk.


  1. Connect the SSD to the iMac.
  2. Turn on the iMac, and immediately press and hold Option + Command + R.
  3. Connect to WiFi in the top right corner.
  4. Go to Disk Utility
  5. Select "View" > "Show All Devices".
  6. Select the main SSD drive. It will be the top, non indented drive in the "External" section. Its name will end in "Media".
  7. Click "Erase", and input the following:
  8. Name: (Could be anything, or a name such as "macOS".)
  9. Format: APFS
  10. Scheme: GUID Partition Map
  11. Click Erase
  12. Quit Disk Utility.
  13. Select "Reinstall macOS".
  14. IMPORTANT: Make sure to select the new external SSD as the installation target for macOS.
  15. Let the process complete.


POST-INSTALL:

  1. Now, to make the new SSD your default "boot" or "startup volume", go to System Preferences > Startup Disk, and select the SSD. Click Restart.
  2. Now, download your data from iCloud.


Just keep the SSD connected at all times!


Cheers,


Jack

Reply
User profile for user: Breezez
Breezez Author
User level: Level 1
8 points

Mar 20, 2021 1:15 PM in response to rkaufmann87

Thanks for your advice. This does seem pretty simple this way. Couple of add on questions?


1) would it make sense to use terminal to undo the fusion drive link? Then reformat that drive?


2)if the internal blade drive is working should I use it as my boot drive and the SSD housing your recommending as my storage drive location, or is 128GB to small?


3) Will the bad HDD drive cause issues with my fan. I noticed it kicks on pretty high since drive crapped out.

Reply

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

Fusion Drive Issue - Need to Upgrade

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.
Learn more Sign up