Downgrade from Monterey to Big sur via USB disk

Moreplavec wrote:

I'm sorry, but i can't find the point. I have working Macbook Air M1, i just need to downgrade or make clean installation with Big Sur. Notebook is alive, able to boot and boot to recovery mode. Your link is, if i get it right, about two computers (i don't have other usb-c macbook) and how to flash them each other, if one is dead or in troubles. Please, can you be more specific how this can help with clean installation of Big Sur to my Macbook? I have USB disk and internet (and old mbp 2013 late), and it's all i have to make clean install and looking for help.

To revert to a previous macOS you have to erase/reformat/initialize the parent drive

How to erase your Mac Erase and reinstall macOS - Apple Support

How to reinstall macOS from macOS Recovery - https://support.apple.com/en-us/HT204904

If your mac has a T2 chip make some change

About Startup Security Utility - Apple Support

Moreplavec wrote:

• Greetings,

because of problems with Monterey i tried to downgrade to Big Sur. I have Macbook Air M1 (8/512). I followed these steps:

reboot

holding power button while Install macOS Big Sur• , than choosed

• logged in to my account (password needed)

• selected Install Big Sur

• Agreed licence

• selected Macintosh HD as disk to install

problem: popup says: • The volume cannot be downgraded.

So i quit install and started Disk utility to delete Volume Group. But when i selected to delete Volume group i got big warning which says:

https://discussions.apple.com/content/attachment/9b6049a6-35b1-4f73-9074-a4bef74b32ca

So, does anybody know how to reinstall to Big Sur with USB disk? I found, somewhere, that new M1 is unable to install from internet.

So, my question is: how to get Big Sur again as clean install? With intel Macbook it's easy, but M1 is new to me and I don't know how to procede to get clean new Big Sur from USB or internet. I found some YT videos, but with old settings to enable USB install, M1 currenty don't have such dialogues.

Many thanks for any help to get my new notebook again usable.

if your machine shipped with macOS Monterey, you can not install/and run and older macOS. This is not supported.

How to erase your Mac Erase and reinstall macOS - Apple Support

How to reinstall macOS from macOS Recovery - https://support.apple.com/en-us/HT204904

The M1 can presents some issues—

https://support.apple.com/guide/apple-configurator-2/revive-or-restore-a-mac-with-apple-silicon-apdd5f3c75ad/mac

if you still have issue on the fly you can Call Customer Support (800) MY–APPLE (800–692–7753)

Moreplavec wrote:

No, my Macbook Air M1 was shipped with Big Sur and i want to downgrade, but after Monterey upgrade it looks like it's blocked. Please, see my whole store, where it's shown what it says. I don't know how to reinstall even if i have Big Sur downloaded and USB ready. The process is with M1 chip somehow different.

Yes pleas read the whole post:

The M1 can presents some issues—

https://support.apple.com/guide/apple-configurator-2/revive-or-restore-a-mac-with-apple-silicon-apdd5f3c75ad/mac

Moreplavec wrote:

I'm sorry, but i can't find the point. I have working Macbook Air M1, i just need to downgrade or make clean installation with Big Sur....

There are two methods.

Erase the internal macOS container, then install Big Sur and restore your system from your Time Machine backup at a point before the upgrade. A variation of this, if you have a second Mac, use Apple Configurator 2 and restore the Mac back to the last Big Sur release and use Migration Assistant to restore data and apps from the Time Machine backup just before you upgraded.

The second which might work, provided you have sufficient disk space, create a second partition and install Big Sur on that partition and then use Migration Assistant to copy apps and data from the Monterey install, set Big Sur partition as the boot disk. Once all done and working, then you can get rid of the Monterey install and restore the space back to Big Sur.

You cannot install an older version of an OS on top of a newer OS, as is true with most apps as well.

Hi Moreplavec,

It is safe to click Erase Mac in the screenshot shown. Your Apple silicon Mac has two additional APFS containers that hold some firmware and a backup copy of macOS Recovery, respectively, and it is smart enough not to erase those two containers. This ensures that you can still reinstall macOS after you erase.

Once you click that button, your Mac should restart. When it starts up again, shut down your Mac, then press and hold the power button (or Touch ID) until Startup Options appears. Connect your bootable installer for macOS Big Sur and click Continue. Activate your Mac if prompted, then the macOS Big Sur installer should automatically open.

Hope this helps!