Mac Mini - Is it possible to pull data off a Fusion drive when I already removed the SSD portion? (But have USB enclosure)

[troy14]

Hey all,

Did something stupid here and trying to see if I can reverse the damages.

I wanted to upgrade my parents Mac mini and thought I had a Time Machine backup on a local disk but it turns out it hadn't been plugged in for a while, stupid me for not checking (parents, ugh!)

I took apart the mini and upgraded the drive (removing the fusion drive 128gb SSD) to a 1TB SSD (while keeping the 1TB HDD inside) and installing Mac OS on the SSD. I DID NOT touch anything on the SSD or HDD yet.

Went to restore it and that's when I found out I made a dummy mistake.

My question is instead of taking apart the mini again, rehooking it all up, etc., can I somehow restore the Fusion drive (I have a SATA to USB enclosure for the 128GB SSD) and access the data or create a backup?

 

[Fishrrman]

There's a -chance- that if you restore the Mini to its original configuration, it -might- boot up again.

But this will work ONLY if you have not done anything else to the original drive that you took out, or the one you left inside.
So... open it up and put the original SSD back in.

If it boots, IMMEDIATELY back up the fusion drive to another drive using either CarbonCopyCloner or SuperDuper (NOT time machine).
Then test the cloned backup (see if it boots).
If the backup is good, NOW do surgery on the internal drives.

If you install a 1tb SSD, I would recommend that you DO NOT "re-fuse" the internal drives.
Let them exist as "two standalone drives".

If the Mini DOES NOT BOOT after restoring to the original configuration, you might try booting to INTERNET recovery (command-OPTION-R) and running disk utility's first aid feature.

If that doesn't work, my guess is you're not getting the data back.
In that case restore from the tm backup you have (even though it may be old), and let things go at that.

 

[Brian33]

My question is instead of taking apart the mini again, rehooking it all up, etc., can I somehow restore the Fusion drive (I have a SATA to USB enclosure for the 128GB SSD) and access the data or create a backup?

I am quite sure you will not be able to restore the Fusion drive by putting the original SSD into a USB external enclosure. First, my understanding is that you can't create a Fusion drive with part of the drive connected via USB (you can if the drive is in a Thunderbolt enclosure, at least with some versions of macOS). Second, if you use the Terminal commands to create a Fusion drive, access to all existing data on the storage media is "lost".

Your best hope is to re-install the original SSD exactly as it was and hope that nothing on the SSD nor the original HDD was touched in the slightest.

Because the Fusion drive magic works at the block level and not at the file level (meaning that one file may have some blocks on the SSD and some blocks on the HDD) I think if the re-assembly does not work you have next to no chance of recovering any data from the devices. I doubt even DiskWarrior would work, although it might be interesting to try...