Booting different versions of MacOS from USB on Apple Silicon

[elliots11]

The short and sweet of it is: I would like to boot my Macbook Pro M1 Max from an external USB that I'd set up to use a different version of MacOS than what's running internally. I've done that with Intel Macs before and it went ok, is there anything different with Apple Silicon Macs that I should know before I dive in? Like are there security features that would prevent this on Apple Silicon Macs?

The longer version goes - I have an M1 Max MBP running 12.7 Monterey. I would like to update it to 15.x Sequoia, but probably it'll end up going to 14.x Sonoma because I've read my main software I run for work is going to play nicer with Sonoma right now. Would it be possible to install 15.x Sequoia on a USB and boot from that as needed while keeping the internal SSD loaded with 12 Monterey or 14 Sonoma? 15 Sequoia has some features I'd like to use for personal stuff but not work stuff.

I might also like to have and keep an external USB boot drive to act as my personal or secure stuff while keeping work only stuff on the internal, sort of turning 1 computer into 2 or more. I suppose virtualization could be used to enable some of this, but I'm exploring this idea.

 

[bogdanw]

It’s a nightmare on Apple silicon. It requires permanent Internet connection, even if you use a bootable installer. It has to not be connected to the DFU port. And even if you respect Apple’s requirements, the installation might still fail. After that, it’s OK

“If you're using a Mac with Apple silicon, plug your storage device into any compatible port except the DFU port. Learn how to identify the DFU port. After macOS installation is complete, you can connect your storage device to any compatible port, including the DFU port.”

Install macOS on an external storage device and use it as a startup disk
https://support.apple.com/en-us/111336

How to identify the DFU port on Mac
https://support.apple.com/en-us/120694

Create a bootable installer for macOS
https://support.apple.com/en-us/101578

 

[Fishrrman]

It can be done.
It's more complicated, as bog says above. Pay attention to the part about "DFU ports".

If you're going to try, use a USB3.1 gen2 enclosure with an nvme blade SSD inside.

DO NOT attempt this with:
- a USB flashdrive (even a fast one)
- an SD card
- a platter-based hard drive

I don't believe any of the above will work, either due to a lack of proper controlling circuitry (flashdrive and SD cards) or speed (HDD).
You want an SSD...

It's probably best done by booting from a flash drive installer.
I recommend the free, small utility named "Mist", which can download the OS installer AND create the flashdrive in one operation.

Personal experience:
I have a bootable 2.5" SATA SSD (in a USB3.1 gen2 enclosure) with Sequoia installed that will boot and run my MacBook Pro (m1pro) 14" which normally runs Sonoma.

 

[elliots11]

It can be done.
It's more complicated, as bog says above. Pay attention to the part about "DFU ports".

If you're going to try, use a USB3.1 gen2 enclosure with an nvme blade SSD inside.

DO NOT attempt this with:
- a USB flashdrive (even a fast one)
- an SD card
- a platter-based hard drive

I don't believe any of the above will work, either due to a lack of proper controlling circuitry (flashdrive and SD cards) or speed (HDD).
You want an SSD...

It's probably best done by booting from a flash drive installer.
I recommend the free, small utility named "Mist", which can download the OS installer AND create the flashdrive in one operation.

Personal experience:
I have a bootable 2.5" SATA SSD (in a USB3.1 gen2 enclosure) with Sequoia installed that will boot and run my MacBook Pro (m1pro) 14" which normally runs Sonoma.

Thanks for both your replies, I’m glad I asked. I figured there’d be something.

When you’re recommending the USB 3.1 gen2 enclosure are you specifically recommending like a USB-A connection with a USB-C adapter, or just to make sure that the USB-C enclosure supports the USB3.1 gen2 protocol?

I’d imagine the protocol but who knows? Better to ask and be sure

 

[Change Agent]

I followed this to the letter and , that is how I did it in the first place, and it does not work. after it almost finishes I get this window and when I click Restart it loops and returns to this window.

any idea as to how to fix?

 

[uacd]

I followed this to the letter and , that is how I did it in the first place, and it does not work. after it almost finishes I get this window and when I click Restart it loops and returns to this window.

View attachment 2574008

any idea as to how to fix?

Well it is an old bug but seems to have reappeared. As soon as you install MacOS from usb drive, when it reboots and you see black screen, pull out the usb stick, so it continues to boot into installation. Maybe this helps?

 

[uacd]

I’m glad I asked

I am actually glad you asked! I wanted to try it out as well one day, but seems like it is not as easy of a journey as on Intel Macs.

Maybe the only good option is to create dualboot on main internal SSD if you have space left. However it might introduce weird DFU bugs, I recently got a bug when I downgraded from Sequoia to Monterey when my brightness control stopped working correctly and worked only after closing the lid/manual sleep mode, reboot didn’t help. Had to install Sonoma permanently, well at least it doesn’t lag on my M1 Air like Sequoia.

If you are going to try installation, buy a decent external SSD like Samsung T7, it is pretty expensive but will do the job very well without the hassle of enclosure-disk search

 

[Change Agent]

Well it is an old bug but seems to have reappeared. As soon as you install MacOS from usb drive, when it reboots and you see black screen, pull out the usb stick, so it continues to boot into installation. Maybe this helps?

I have no problem getting back to the main internal disk. And if I unplug and select it, after plugging it in again, as the startup disk it tells me is not able to do so.

 

[Change Agent]

I am actually glad you asked! I wanted to try it out as well one day, but seems like it is not as easy of a journey as on Intel Macs.

Maybe the only good option is to create dualboot on main internal SSD if you have space left. However it might introduce weird DFU bugs, I recently got a bug when I downgraded from Sequoia to Monterey when my brightness control stopped working correctly and worked only after closing the lid/manual sleep mode, reboot didn’t help. Had to install Sonoma permanently, well at least it doesn’t lag on my M1 Air like Sequoia.

If you are going to try installation, buy a decent external SSD like Samsung T7, it is pretty expensive but will do the job very well without the hassle of enclosure-disk search

I do use the T7 it is a good piece of kit and I have several of them. Agreed Intel and before was easey. I remember the days where you just dragged and dropped the OS stuff across to an other disk.

I also found this How to Create Boothable disk and followed that, but again I get that loop.

Anybody any tips?