Fix Your Stuff Community Store

Model A1419 / Late 2012 / 2.9 & 3.2 GHz Core i5 or 3.4 GHz Core i7 Processor, ID iMac13,2

330 Questions View all

Options

HDD part of Fusion Drive replaced, without breaking Fusion Set

I removed / replaced the failing 1TB HDD part of Fusion Drive without 'breaking the fusion set' in Terminal.

The new HDD does not show in either Disk Utility & Terminal (diskutil list)

In Disk Utility, for example, all that shows is:

Internal:

Apple SDD SM128 Media

- Container disk2

- Mac HD

Disk Images

- Apple disk image Media

The new HDD is 4TB Toshiba HGST SATA 3, complete with the OWC sensor kit;

I can hear the drive running + it shows up as a Windows Drive, when I restart using a bootable USB.

Have tried SMC & PRAM resets to no effect.

Cannot reconnect original 1TB HDD as it was failing it went straight to recycling

Not sure if its related, but 3 out of the 4 USB ports are not responding.

Yep - I dearly wish I'd read up on Fusion Drives beforehand.

All I want is a working machine - its primary purpose is to store photos, video files & family stuff; which I don't have room for on my MBP.

Any advice welcome

Answer this question I have this problem too

Is this a good question?

Yes No
Score 1
Add a comment

1 Answer

Filter by:
Most Helpful Newest Oldest

Options

You’ll need to create a bootable OS installer drive (USB drive) following this guide from another Mac: How to create a bootable macOS Sierra installer drive You’ll need to stick with MacOS Sierra as Apple still hasn’t fixed High Sierra to work with Fusion Drives (the coming release this fall should fix that)

I’m suspecting the reason your USB ports didn’t respond was the OS you used (MS Windows) didn’t have the needed drivers if you where using MacOS your system may have gotten hit by a surge or lightning strike which went through your ports burning them out. That will take someone to debug the logic board or you’ll need to replace it, hopefully thats not the case.

Make sure your system and the peripherals are plugged into a good surge suppressor (or UPS) You may need to check your house wiring and look at installing a whole house surge arrestor in the breaker panel.

OK getting back to the drive…

Using the good USB port boot up under the installer and run Disk Utility and reformat the drive to GUID partition mapping and create a Journaled File system. You’ll need to then install the OS onto the HD drive. Whats not intuitive is the HD is the base drive of a Fusion Drive set. So until its setup with the OS we can’t rejoin the SSD to it.

Now the fun part we also need to reformat the SSD with no OS! And we also need to test the system the break the Fusion set How to split up a Fusion Drive Once you get this far you should be able to restart your system on the internal HD. You may need to boot up with the Startup manager Holding the Option (⌥) to select it. After restarting finish setting up your drive. Now to get the Fusion Drive re-established follow this Apple T/N: '''How to fix a split Fusion Drive'''. That should do it!

Reference: '''Mac startup key combinations'''

Was this answer helpful?

Yes No
Score 0

1 Comment:

Hi Dan - Thanks for the prompt responses.

SMC & PRAM have been reset previously, without any effect.

The iMac has be restarted both in 'recovery mode' & from a bootable USB MacOS High Sierra installer drive.

The new drive does not show in Disc Utilities. Hence my seeking advice how to use 'Terminal'.

As I don't (& have never) run Windows on this iMac, it won't load.

The iMac has always been surge protected.

T commands in 'How to Split....' get the response 'No core storage found' - confirming that I've already split the drive.

'How to fix a split FD' doesn't work as new drive doesn't show in diskutil list.

My best guess / next step, is to re-open iMac, remove & reformat the new drive in Mac OS Extended Journaled; reinstall & try again.

by

Add a comment

Add your answer

pmmcq will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 1

All Time: 577