Question: Installation on external drive
I'll try to keep this as simple as possible but it's a little complicated.
I have two MacBook Pros, which I will call "Old MBP" and "New MBP." Old MBP has a problem, probably a bad hard drive, and so I'm trying to boot it up from an external drive. To do this, I need to install High Sierra (which is the most recent version of macOS that Old MBP can run, on an external drive. New MBP, however, is running Mojave, so I can't run the High Sierra Installer on New MBP. So I created a bootable USB installer for High Sierra, restarted New MBP with it as my startup disk, and tried to install High Sierra on the external drive. This seemed to be working great but when the installation hit the point when it had to restart, it used the internal drive on New MBP, so the installation of High Sierra on the external drive didn't finish. Now I have a folder on the external drive called "macOS Install Data" but I don't know how to get it to complete the installation on that volume. Can you help?
Thank you!
Daniel
