Fusion Drive: replaced blade SSD can’t install macOS now

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Fusion Drive: replaced blade SSD can’t install macOS now

Hopefully I can figure this out with the community help!

Have a a1419 Late 2014. The Fusion Drive failed and it was specifically the blade SSD 128 gb portion. Figured I would try to replace myself and ordered a used MZ-KPU1T0T/0A6 1tb blade SSD from eBay. I was able to complete the task (somewhat of a process)and was pretty proud of myself. But now I cannot seem to re fusion the drives or upload a working macOS on any drive (unfused). Getting an error in terminal that states I’m trying to do an upside down fusion and it won’t complete. My question is am I being stopped because my blade SSD and HDD drive are the same size? Is there a workaround? Or do I need to get a different larger HDD to replace my now too small 1tb HDD to let fusion work.

iMac 27″, OS X 10.10

Posted on Aug 20, 2024 7:44 AM

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Answer 1

Top-ranking reply

den.thed

Level 10

96,772 points

Aug 20, 2024 8:19 AM in response to Seattle-Shawn

Do not refuse the drives. Use the 1T SSD as your startup disk and then use the 1T HDD for extra storage or your large Music, Photos or Movie Libraries.

Startup in macOS Recovery Mode format the 1T SSD and then install macOS on it.

Use macOS Recovery on an Intel-based Mac - Apple Support

Use Disk Utility to erase an Intel-based Mac - Apple Support

How to reinstall macOS - Apple Support

Then migrate your user data to the new 1T SSD from your backup.

Transfer to a new Mac with Migration Assistant - Apple Support

Then Erase the 1T HDD and use it for extra storage or for your large User Libraries.

Free up storage space on your Mac - Apple Support

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Answer 2

Aug 20, 2024 8:07 AM in response to Seattle-Shawn

If I was you, and I had installed a 1 TB blade SSD inside of the Mac, I would not try to recreate the Fusion Drive.

Leave the drives separate. Use the internal 1 TB blade SSD as your startup drive and the internal hard drive (if it is in working condition) as a secondary drive. When SSD space was really scarce and expensive, there was a benefit in putting up with the increased complexity and software fragility of a Fusion Drive. Now? Not so much …

I hope you have bootable backups to work from when restoring the Mac, as replacing either hardware component that contributes to a Fusion Drive effectively destroys the ability to use the Fusion Drive volume.

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Answer 3

BDAqua

Level 10

251,409 points

Aug 20, 2024 8:31 AM in response to Seattle-Shawn

If you're trying 10.13 High Sierra or less it needs Mac OS extended Journaled, GUID Parition scheme, APFS for Mojave upwards.

I have seen jumping too far a problem, I'd try 10.11 El Capitan first.

Maybe Format the drive ExFAT 1st then Mac OS extended Journaled.

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Answer 4

den.thed

Level 10

96,772 points

Aug 21, 2024 10:20 AM in response to Seattle-Shawn

Good work. 👍

Yes I would re-format the internal HDD to free up all of the space on it.

Then I would check it's health with Drive DX from > https://binaryfruit.com/drivedx

If the HDD is healthy, I would use it for extra storage or for my larger Photos, Music or Movie Libraries.

Move your Photos library to save space on your Mac - Apple Support

Change where your music files are stored on Mac - Apple Support

Move your iMovie for Mac library - Apple Support

In this case, make sure that you have a good backup of everything on both internal drives.

If the HDD is not healthy, then just let it sit empty or... go back in and replace it as well.

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Answer 5

den.thed

Level 10

96,772 points

Aug 20, 2024 8:32 AM in response to BDAqua

BDAqua wrote:

If you're trying 10.13 High Sierra or less it needs Mac OS extended Journaled, GUID Parition scheme, APFS for Mojave upwards.

👍

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Answer 6

Aug 20, 2024 8:15 AM in response to Servant of Cats

Thanks! Im ok just using the 1tb SSD blade as you suggested, but I am unable to either format it correctly or figure out how to load a macOS ( I was using Big Sur) on it. I’ve read tons of threads and just cannot figure it out.

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Answer 7

Aug 21, 2024 8:12 AM in response to Seattle-Shawn

Thank you all for the help & advice. I have left it un-fusioned and was able to install the macOS on the blade SSD. Installed Big Sur, updated what I could and then migrated from my Time Machine. That took an incredible 4.5 hours! Everything seems to be working as it’s supposed to. One last question: what’s the best utilization of the HDD still inside (1tb), and what is the best/easiest way to access it? Does it need formatting and if so, what kind.

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Answer 8

BDAqua

Level 10

251,409 points

Aug 20, 2024 8:13 AM in response to Seattle-Shawn

Agree with SoC.:)

What Format is the new sSD & which Os are you trying?

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Answer 9

Aug 20, 2024 8:19 AM in response to BDAqua

I’ve tried formatting to both extended journal and apfs. I’m trying to reload Big Sur. Is the leap to Big Sur the problem in your opinion? I think it came with Yosemite originally.

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Fusion Drive: replaced blade SSD can’t install macOS now

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