I have a late 2012 Mac Mini running macOS Sierra (10.12.6). It came with a 1TB fusion drive. I recently removed that drive to replace it with a 960GB SSD. All is working fine except for two issues.
The old fusion drive shows in the left column of Disk Utility (as APPLE HDD...).
If I restart while hiding down the option key, it shows up there too.
In Terminal, in diskutil list, it shows up as disk0. The replacement SSD shows up as disk1.
Is there anyway to keep the 'phantom' disk from showing up?