Just bought an iMac with 2 solid state drives. How do I use it?

Question

I just bought an iMac with internal 2 solid satte drives - 128 GB Flash Storage and 1 TB SSD. The modification was the previous owner's idea as it was sold new with a 2TB Fusion Drive. What is the best way to use it, as it's my first time with 2 internal disks? I wanted to import everything from my MacBook through Time Machine, which was impossible, because I had about 180 GB of files and I couldn't boot the iMac from the SSD.

Is there any way to have everything on the 1TB SSD and completely disregard the 128 GB disk?

If not, how does one use 2 disks correctly? I am so green I don't even know how to save files to the SSD other than dragging them to it through the finder. How do I go about saving files on my desktop, but have them reside on the SSD?

Answer 1

Many iMacs and other Macs have what is called a "Fusion Drive". These are made up of a small-capacity SSD (solid state disk) and a large-capacity HDD (mechanical hard drive).

Originally, they would be formatted in such a way that the OS would present them as one continuous volume. The point was to gain the benefit of the fast SSD and the large storage of the HDD.

The previous owner has replaced the mechanical drive with a new large SSD.

Each separate volume can have an OS installed on it; otherwise, they present themselves as sub-folders of the /Volumes folder. You can store whatever files on them you like.

Answer 2

I think I found the solution! I had to start the computer while holding CMD + R which allowed me to erase the disk and reinstall the OS. At that point I could choose from the 2 disks on which to install and I chose the 1TB SSD! Unfortunately I was unable to migrate the files because the process got stuck both times at around 70%. I am currently typing this on my iMac with everything installed on the 1TB drive :)