iMac 27” late 2013, pure ssd how to change to fusion drive again?

[Flop01]

Hello, my iMac was originally born with fusion drive but went defect a few year ago and replaced with a pure ssd drive. My problem is that i cannot update the system due to the installation program inform “disk is not supporting core storage configuration” as i read it i cannot update the system unless i have a fusion drive installed again?

Is there a workaround to reestablish to fusiondrive again?

 

[Fishrrman]

What size was the original fusion drive?
1tb?
or... 2tb or 3tb?

 

[Flop01]

I dont know, but will check up.
but have seen that i have 2 ssd's the first 128 GB and the second is 500 GB. Can they be setup at fusion drive?
[automerge]1581267573[/automerge]
I checked the serial no at apple - it said Storage: 3 TB, Fusion Drive

 

[Fishrrman]

I don't think that you need to re-fuse them.
However, you might considering installing a copy of the OS onto the 128gb drive. This is the factory-installed "SSD portion" of the original fusion drive.

I've heard that some OS updates can't be installed unless the installer finds an original-Apple-installed drive "in the right place" -- has something to do with machine/drive IDs, firmware, etc. I could be wrong.

Could you tell us exactly WHAT upgrade/update/software gave you the error msg?

 

[Flop01]

The Imac was originally equipped with 3TB Fusion drive.
Is running High Sierra 10.13.6.
Cannot update to Mojave nor Catalina

How can i find out which drive the operating system are installed at?

 

[Fishrrman]

"How can i find out which drive the operating system are installed at?"

How about checking "About this Mac" (Apple menu)?