But it boot straight into the Mojave drive, bypassing the external drive.
So I choose the external drive and click restart. So I let it boot into Mojave and go to System Preferences/Startup Disk, and I was able to see the external drive there. Restart with Option key shows only the Mojave internal volume, the High Sierra external clone does not show. But I found 2 major obstacles.īooting up using the external clone drive does not work.
After I upgraded to Mojave I immediately noticed something not working right(1), so I decided to downgrade back to High Sierra using the clone. I verified the external drive and see it boot fine. Two surprises: Can’t boot up from external backup Can’t reformat drive from APFS to HSF+.īefore upgrading to Mojave, I made a full disk clone of the High Sierra HD (2014 Mac mini, no T2 security chip) to an external drive.