Booting from macOS from an External Hard Drive?

[camelia]

Hello,

My client wants to boot from her external SSD macOS Sonoma an continue in the internal SSD of a MBP M2 Pro with macOS Ventura
My client want to install in the internal SSD only the app she needs but not from the Apple Store (DaVinci_Resolve_18.6.5_Mac.dmg, Firefox 123.0.pkg.. ) AND in the External Only Apps from the Apple Store

Please don't ask me why, that is she wants, and I have to deal with it

Also both SSD will be Frozen (Deep Freeze) after finish installing or after finish updating each time a new version updates.

Deep Freeze Mac Release Notes

Explore the release notes of Deep Freeze Mac in Faronics' Document Library for update details.

www.faronics.com

I have sell to her 1 SSD Enclosure 40Gbps M.2 NVMe with a 8TB SSD and 2 Deep Freeze Licenses
But I have not idea if this is possible now, since I starting watching YT Videos my head and ideas are a mess

Can someone please guide me?

Thanks
Camelia
@bogdanw

​

 

[Bigwaff]

Can someone please guide me?

What specifically do you need guidance in doing?

My client

… implies you are charging a fee for this service? 🤔

 

[camelia]

… implies you are charging a fee for this service? 🤔

I will not bother to answer you the first question

Do you have any problem to ask in this forum a question where implies charging a fee for a service?

 

[bogdanw]

I don’t see why it shouldn’t be possible.
Configure Ventura as desired and install Deep Freeze.
Then download, install and configure Sonoma on the external disk.

Apple doesn’t provide much on this “If you can’t install macOS on an external disk”https://support.apple.com/guide/mac-help/mchlp2967/

 

[winxmac]

I have done this on an intel mac but not on Apple Silicon...

I initially wanted Yosemite and Catalina on separate drives but now I just use the internal drive for Catalina and Windows 10 without using Boot Camp assistant...

 

[Fishrrman]

OP:

Please tell us WHICH Mac your client has, and WHAT YEAR it was made.

Apple Silicon Macs ("m-series" Macs) are more complicated when you wish to boot from an external drive. Some people can't get them to boot at all that way.

Intel-based Macs are MUCH easier when you want to "boot externally".