So I recently installed a Samsung 850 Pro 256GB SSD in my late 2012 Mac Mini using OWC's data doubler, combining my original 500GB regular hard drive. I successfully boot from the SSD, and use my 3 or so External Harddrives for files and documents and photos, etc. Question is, what the heck do I do with my internal 500GB hard drive? It's just sitting there. Granted, it still has my original OS and several files, but A. the OS (sierra) is on my SSD and 2. All files are backed up on my externals, including a FireWire 500GB solely purposed for time Machine for my Samsung SSD content. So I'm pretty sure I could just erase my original 500GB internal without any hickups (right??) and just use it like I use my external hard drives, for files, large collections (movies, music, photos, etc.) I've read about "Fusion" drives and "make your own" but also that this is false, that you can't make a real fusion drive from a third party installation. I've also heard of hybrid drives, but don't really know what they are, though maybe that's what I already have. Sooooooo........any advice? How to best utilize my 2 internal drives (1 256GB SSD, 1 500GB HHD)??