MP 7,1 Adding Different OS on a Separate Internal Drive?

[choreo]

I am contemplating this and need advice.

I have a 2019 Mac Pro with 1TB Apple SSD booting in latest version of Monterey. I also have a Samsung 1TB SSD installed on a Sonnet PCI card which (supposedly) is doing an auto daily CCC backup of the startup drive (not sure if it is bootable - never tested it).

For a number of reasons, here is what I may want to do if feasible...

IF my Samsung CCC Monterey Clone is truly bootable, I would like to completely erase the Apple Installed SSDs and start over from scratch by installing Sonoma and reinstalling ALL my apps fresh (and leaving out some suspect apps I now have). I am assuming I will need to shut down my business for the better part of a week to attempt this as I have so many apps!

Is this doable? i.e. I want to keep a bootable Monterey OS drive primarily to continue running Quickbooks 2019 frozen in time and do everything else on the Apple SSD running Sonoma. At best this will be a major PITA rebooting several times a day just to do bookkeeping (thanks Intuit!). Alternately, I may just want to do the same thing and install a fresh copy of Monterey and all my apps on the Apple installed SSD's, but I would need the Monterrey CCC clone drive just in case so I could revert.

I suspect that using Migration Assistant and Time Machine restores over many years has resulted in thousands of old files being carried over that may be causing me issues I am experiencing, but apps like Adobe CC don't make this restoration easy!

Thoughts?

 

[Bigwaff]

Why not use Parallels. Create VM, install Monterey and your apps. Best of both worlds.

 

[CurtisBilly]

The Apple SSD can have more than one version of macOS loaded onto it:

Use more than one version of macOS on Mac - Apple Support

If you install a compatible macOS on an additional internal or external storage volume, your Mac can start up from either volume.

support.apple.com

If you end up with both Monterey and Sonoma installed, I would only login to iCloud in one of the two versions of macOS, preferably Sonoma. You could have Monterey as a minimal install for just the one piece of software you need.

 

[choreo]

Why not use Parallels. Create VM, install Monterey and your apps. Best of both worlds.

Tried that a few years ago, may give it another try

 

[apostolosdt]

Why not use Parallels. Create VM, install Monterey and your apps. Best of both worlds.

I’m doing that all the time; still, unless you run the Parallels Business version plus lots of RAM, you experience low performance with VMs.

 

[mattspace]

FWIW VMWare Fusion doesn't have any of the limitations of the "home" version of Parallels, and it's free. I'm dipping my toe in the VM world with it, and it's working pretty well. I have Yosemite, High Sierra and Big Sur VMs all seeming to work OK.