Leftover Fusion Drive AS External HD Qs

[zeroq]

Since I have a 2TB Fusion Drive removed after SSD upgrade, I'm thinking of using it as an extra external HD for Time Machine back up etc. I wanted to erase everything and reformat (APFS).

The problem is my iMac doesn't recognize the Fusion Drive/SATA when I plug in using SATA to USB cable. What do you think is going on here?

TIA

 

[TwoH]

Does the drive show up in disk utility? Or does it show up in terminal:
diskutil list
Or
diskutil ap list

 

[zeroq]

No it does not show in disk utility nor desktop; I know nothing about terminal unless I have a step-by-step instruction. 😔

 

[Fishrrman]

OP:
"Since I have a 2TB Fusion Drive removed after SSD upgrade, I'm thinking of using it as an extra external HD for Time Machine back up etc. I wanted to erase everything and reformat (APFS). "

Hold on a minute.
When you did the upgrade, which portion of the fusion drive did you take out?

If all you took out was the platter-based hard drive, you did not "remove" the fusion drive. You only took out the hard drive.

In that case, put the drive into an enclosure or use a USB3/SATA docking station, and use disk utility to erase it to Mac OS extended with journaling enabled, GUID partition format.

It will now work like any other hard drive.

 

[zeroq]

I cloned what was on the Fusion drive HD onto Sam 860 EVO Sata and swapped out. I also swapped the Apple blade to Sam 970 EVO plus.

But why doesn't my iMac recognize the Fusion Drive HD? I can't do anything since iMac doesn't show the Fusion Drive HD anywhere. I simply used a SATA/USB3 cable to connect w/o an enclosure or a docking station just to see; it should still show, no?

 

[Fishrrman]

"But why doesn't my iMac recognize the Fusion Drive HD?"

First off, you do not know what a "fusion drive" IS.

It IS NOT the "drive" you took out of the iMac.
(part of it is still "in there").

A fusion drive is composed of TWO drives (NOT one):
- a small SSD blade drive
and
- a larger platter-based HDD.

They are then "fused" by software drivers in the OS, so that they "look like" a single drive to the user.

As such, the "melded together" fusion drive can be "recognized" by the OS (this means you can see and access the files on it) ONLY while it REMAINS a part of the original fusion setup (which is TWO drives, remember?).

Whatever portion of your original files that were on the HDD portion, are now UNREADABLE and for all practical purposes, UNRECOVERABLE.

You did have a backup, right?

The only thing you can do with the HDD drive now is to reformat it and use it as a "standalone" (non-fused) drive.

 

[zeroq]

Only back up is in the Sam 860 Evo SATA inside iMac where Seagate HDD 2TB used to be (I cloned it to Sam 860 bf installing). As I said, the orig blade that came with is also swapped out w Sam 970 EVO plus. I should be okay, yes? So far everything seems to work fine except the blade Sam 970 EVO plus 1TB just sits there w nothing/no activity in it (I guess until I store something in it) and iMac is using Sam 860 SSD SATA as Macintosh HD to boot up etc.

I understood Fusion Drive to be something like what you described but I don't know in detail how Sam 860 and Sam 970 would work ie together or separately (Latter is what I'm assuming).

Still, iMac isn't recognizing the HDD, that was the Fusion Drive bf I removed it, as anything at all, zilch. There is a possibility that there is a short in the USB3/SATA cable (though I just bought and used it to clone to Sam 860 so I doubt it but possible; The connector lights flash on the SATA plug.) So, there shouldn't be anything preventing from showing the original HDD drive as a drive? If so, I'll order another SATA/USB cable to double check.

 

[zeroq]

I bought a Wavlink Dual Bay Docking Station and now the (Formerly Fusion Drive) HDD shows in disk utility. I've erased/reformatted/partitioned and it's ready to go. Apparently the SATA cable I ordered shorted I believe... or could be something else as it worked fine cloning from HDD to SSD; I'm returning it.

Thanks again. 👍