2019 iMac SSD upgrade, Fusion as secondary??

[SETIBBIG]

I have a 2019 iMac with a 2TB Fusion drive, and I'm planning on booting from a thunderbolt SSD drive, and use the Fusion drive as secondary drive. I'm a photo editor, and I want to split my big library of files from my OS drive for the sake of my time machine backups.

If I use the Fusion drive as a secondary drive, will it still function as a hybrid drive, with the OS deciding how to move files between the SSD and hard drive? Or would I need to split the fusion drive up?

 

[rbart]

Yes, it will work as a fusion drive

 

[Fishrrman]

I would set things up a little differently.

Yes, I would boot and run from the external SSD.

However, I would split the fusion drive into standalone drives:
- 128gb SSD
- 2tb HDD

Now, I would set the internal SSD up as an "alternate boot drive" with OS, apps, and a basic account.

I would use the 2tb HDD for the "library storage" and extra storage.

WHY I would do this:
If for some reason you get into a situation where you can't boot from the external SSD, you can now boot IMMEDIATELY from the INTERNAL SSD, and go to work on the problem. It will always be "there", for a "moment of need".

But then again, your external SSD is never going to have problems.
Right...?
Right...?

 

[larzy]

How would one go about doing the split of the fusion drive? I’m afraid to mess it up but I’m in the same situation and I thought about using a Samsung T5 ssd for booting