How do I enable external boot on Mac Studio 2025 with M4 chips for professional workflows?

Objet : Mac Studio 2025 – Le démarrage externe est bloqué sans avertissement, une régression inacceptable

Message :

Je constate avec frustration que les Mac Studio 2025 (puces M4) interdisent désormais le démarrage (boot) depuis un disque externe, même parfaitement cloné (APFS, préparé sur un Mac Silicon, avec Carbon Copy Cloner).

Problème confirmé :

  • đź”’ Aucun disque externe n’apparaĂ®t en maintenant la touche ⌥ Option au dĂ©marrage.
  • ⚠️ L’option "Autoriser les mĂ©dias externes" a disparu du Mode RĂ©cupĂ©ration (Options de dĂ©marrage > SĂ©curitĂ©).
  • đź’ľ Les clones externes fonctionnent uniquement en restauration interne (via Migration Assistant), mais plus en dĂ©marrage direct.

Impact réel :

Cette restriction brise des workflows professionnels critiques

(tests logiciels, récupération d’urgence, environnements isolés). Elle

force à acheter des Mac supplémentaires là où un simple SSD externe

suffisait avant.

Demande Ă  Apple :

  1. Documentez officiellement ce changement (aucune mention dans les notes techniques).
  2. Rétablissez l’option de boot externe, ne serait-ce que via une autorisation sécurisée (Touch ID + mot de passe admin en Mode Récupération).
  3. Justifiez cette décision si elle est définitive – la sécurité ne doit pas tuer la flexibilité pro.

Preuves à l’appui :

  • TestĂ© avec 3 disques (SSD Thunderbolt/USB4, APFS, macOS Sonoma/Sequoia).
  • Aucune erreur logicielle dĂ©tectĂ©e (bputil -v valide le volume, mais le firmware le bloque).

Solidarité recherchée :

Si vous êtes aussi concerné (Mac Studio 2023/2024/2025), signalez-le via Feedback Assistant et partagez ce message. Plus nous sommes nombreux, plus Apple devra réagir.

#Apple #MacStudio #BootExterne #Regression



[Re-Titled by Moderator]

Original Title: blocage professionnel

Mac Studio (M4 Max, 2025)

Posted on Jun 3, 2025 9:03 AM

Reply
6 replies

Jun 3, 2025 9:47 AM in response to visuelaudio

Install macOS on an external storage device and use it as a startup disk - Apple Support


during this process, you will need to select Reduced Security in the Startup Security Utility for Apple-silicon Macs


Change security settings on the startup disk of a Mac with Apple silicon - Apple Support


AND


Most cloned copies of MacOS are forbidden, you must install that MacOS from fundamental sources.



Jun 3, 2025 7:58 PM in response to visuelaudio

Install macOS on an external storage device and use it as a startup disk - Apple Support


This Apple Support article seems to indicate that you can boot an Apple Silicon Mac from an external drive. When preparing the external drive, you must take care to plug it into a port other than the DFU (diagnostics and firmware update) port (see article for details).


Note: there is a forum thread suggesting that Apple Intelligence is disabled when booting from an external drive.


Why is Apple Intelligence not supported o… - Apple Community

Jun 3, 2025 10:09 AM in response to Grant Bennet-Alder

Hello, thank you, but this doesn’t work on the Mac Studio

M4—though it’s possible on an M2. Currently, I have to use Migration,

and this causes errors in Pro Tools. I never had this issue before. I

used to boot from my external drive, format the internal drive, and then

transfer my disk image. Everything worked perfectly until I bought a

Mac Studio M4. I’m going to sell this M4 Mac because, as several forum

threads have pointed out, it’s no longer possible to boot from an

external drive.

Jun 3, 2025 8:17 PM in response to visuelaudio

Other articles of interest:


Michael Tsai (Blog) – How External Bootable Disks Work With Apple Silicon Macs

The Eclectic Light Company – Create an external bootable disk for Apple silicon and Intel Macs


"All Macs with Apple silicon chips can start up from a bootable external disk without reducing their boot security using Startup Security Utility. To do so, they use a LocalPolicy system that depends on the user having access to a private Owner Identity Key in the Secure Enclave, making that user an Owner."


Indeed, I don't see anything in the Apple Support articles that explicitly states that you must reduce boot security in order to use an external startup disk. It is just that the Apple Support articles don't go into anywhere near the level of gory details that these two articles do.

How do I enable external boot on Mac Studio 2025 with M4 chips for professional workflows?

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