Booting Late 2014 Mac mini from External Drive
I have a Late 2014 Mac mini with an i7 and 18 GB of memory. Nice little machine. And I replaced the internal Apple 1 TB, 5400 RPM, HD with an SSD. Now this mini really performs. The one thing I was struggling with was finding a way to get it to now boot from an external drive. I read the posting “Use an external SSD as your startup disk with your iMac or Mac mini” (https://discussions.apple.com/docs/DOC-250003583). But seeing how the Late 2014 Mac mini only has one slot for a 2 1/2” drive, reinstalling the HD was not an option.
Here’s what worked. The posting above, “Use an external SSD as your startup disk with your iMac or Mac mini” seems to imply that the Apple HD needs to be internal. Not so! I have an “Install Monterey” USB that I created (https://support.apple.com/en-us/HT201372) so I plugged that into one of the mini’s USB ports. I mounted the Apple HD that I had removed from the mini in an external USB 3.0 enclosure, and connected it to another of the mini’s USB ports. Powered on, held down the option key, and the mini recognized the Apple HD (which had been completely erased), and gave me the choice of booting either from the internal SSD or the “Install Monterey” USB.
Just thought I’d post in case others are struggling with this issue.
Mac mini, macOS 12.6