DISCLAIMER: Forgive me, when I don’t exactly know how tech-savvy someone is, I explain EVERYTHING, just in case. I apologise if it comes across as patronising or belittling. That is not my intention. You might know your way around a computer very well (and you probably do), but I’ll still explain everything just in case someone else stumbles upon this thread, and I want to make sure it can help them too.
Apple hardware (at least, anything after 2014) is notoriously uncustomisable. They do this deliberately so that their software just “works”, and don’t have to write drivers for a million different internal types of hardware. Good for their business model and third-party developers of MacOS software, but terrible for anyone who
Secondly, a lot of their internal hardware are usually custom made for Apple. Even though Apple might say in their tech specs that the iMac has a Radeon GPU, or an Intel i5, they’re NOT the same components/designs that are in the retail versions of those components.
You’ll notice that your CPU has some weird model number (probably ending with an “S”) that you can’t find much info on. That’s because they’re often components that have been custom-made to go into that specific model of Apple hardware. If Apple didn’t want to write software for a certain function/capability of a chip, it would be completely removed from the hardware design. It made production cheaper, but reduced their functionality, so it was kind of a double-edged sword….
It’s a little off-topic, but anyone in the Hackintosh community will tell you that getting MacOS to run on non-Apple hardware is “finicky” at best. Sometimes you’ll even see them actually recommend swapping out your internal hardware to something that actually came inside of a Mac!
It’s highly likely that that’s your Mac. I hope you put 32GB of RAM into it
A bit tongue-in-cheek, but Apple has always been a late adopter of cut copy and paste
It’s probably because that was the only other drive that the installer could find in the machine.
If you have formatted your drive with APFS, resizing that is a bit of a pain. If you’ve used HFS or HFS+, you should be able to shrink that partition with
diskutil (or “Disk Utility”, if you prefer the GUI).
If you still don’t want to play with your internal drive (which I completely respect), have you thought about installing it to an external USB drive?
You can do this. Just for the sake of completeness, you can install Qubes OS onto anything you can store files on. So an SD card, external hard disk, etc. will all be fine. Even a USB flash drive is fine for you to at least “try” it out.
Ideally you want 64GB, but you might be able to get away with 32GB (if anyone wants to correct me on this, please feel free to).
The only thing is, do NOT create a USB qube. Your machine will pass through the USB controller containing the OS, and Qubes OS will implode.
You’re more than welcome to try it if you’re curious, but just be ready to hold the power button down and hard reset it ).
That would allow you to at least give it a go.
You just have to hold the option key down at boot and select “Qubes OS”. The devs actually made a pretty nice icon for that menu, too.