Document how to allow macOS Startup Security Utility to boot on external media
It could prevent from starting on an external media:
The following error message was reported to us (in French):
« Les réglages de sécurité ne permettent pas à ce Mac d’utiliser un disque de démarrage externe. »
This should affect by default, as per https://support.apple.com/en-us/HT208862:
- iMac Pro
- Mac mini models introduced in 2018
- MacBook Air models introduced in 2018
- MacBook Pro models introduced in 2018
It would be good to:
- Have our help desk confirm that this is really happening on such machines by default
- Test one of these machines:
- What's happening by default?
- Does allowing booting from external media works?
- Include this in our installation instructions for macOS
I investigated this a bit more and I think that we can document this without testing it ourselves:
- The error message in English is "Security settings do not allow this Mac to use an external startup disk"
- The Apple doc should be enough to guide us: https://support.apple.com/en-us/HT208198