Chosen Solution
I am running High Sierra on my HDD (750 GB) that I have installed in the optical drive bay. I have an empty SSD (250 GB) in the hard drive bay. The HDD memory (305 GB) won’t fit onto the SSD. How do I copy over only the OS and applications to my SSD from my HDD? Ideally I want to use the HDD as storage to for my iTunes Library, movies, pictures and use the SSD for applications and the OS.
Migrate your Apps only first. Create a new user without all the pictures, movies, downloads and music the migrate it. Sometimes you just can’t get those fat legs into your High School jeans.
The easiest way is to clean install OS X on to the new hard drive. During the process, it will ask you to migrate your old data. This will copy all your old data and applications. The only thing that you may need to do is re-enter activation keys for programs like Microsoft Office.
