Downgrading?

[ivnj]

I have m1 Mac mini 8gb 256ssd. It came with Big Sur. I split the internal drive in half and installed Monterey on half so if I don't like it I can go back to Big Sur. I have it on an external also. But wanted to install it to the internal to see how much faster it was or if my install on the external was bad because some things were not working. But now I can't go back to Big Sur. In startup disk only Monterey shows and no Big Sur partition shows. Either from the internal or external. Only Monterey shows. Big Sur is not corrupted because in recovery mode it asks which partition and which user. So its still there. But it won't boot. If I hold down the power button and wait for the list of drives only my external and internal Monterey show. The partiton with Big Sur does not show. How odd. And I can't install a fresh copy because it says Big Sur cannot be installed from a newer system. And even in recovery mode it says reinstall Monterey and not Big Sur. Super confused.

 

[Realityck]

I have m1 Mac mini 8gb 256ssd. It came with Big Sur. I split the internal drive in half and installed Monterey on half so if I don't like it I can go back to Big Sur. I have it on an external also. But wanted to install it to the internal to see how much faster it was or if my install on the external was bad because some things were not working. But now I can't go back to Big Sur. In startup disk only Monterey shows and no Big Sur partition shows. Either from the internal or external. Only Monterey shows. Big Sur is not corrupted because in recovery mode it asks which partition and which user. So its still there. But it won't boot. If I hold down the power button and wait for the list of drives only my external and internal Monterey show. The partiton with Big Sur does not show. How odd. And I can't install a fresh copy because it says Big Sur cannot be installed from a newer system. And even in recovery mode it says reinstall Monterey and not Big Sur. Super confused.

I would not have done that because of your SSD size, just use a HDD or SDD external to copy a snapshot of the partition with your data/files to. Monterey has different APFS admin authentication then Big Sur.

The Apple store can do a DFU restore once you have your data backed up on a external storage. That will redo the system firmware that is matched to that older OS, go back to one partition and will wipe all your date/files.

Monterey 12.3 should be fine for you when it comes out.

 

[ivnj]

I found this guide to create a bootable flash drive.

Create a bootable installer for macOS - Apple Support

Use an external drive or secondary volume as a startup disk from which to install macOS.

support.apple.com

I then reinstalled Big Sur to the external and over the internal existing copy. Now it shows in the startup disk and both work again.

 

[ZebedeeG]

I would not have done that because of your SSD size, just use a HDD or SDD external to copy a snapshot of the partition with your data/files to. Monterey has different APFS admin authentication then Big Sur.

The Apple store can do a DFU restore once you have your data backed up on a external storage. That will redo the system firmware that is matched to that older OS, go back to one partition and will wipe all your date/files.

Monterey 12.3 should be fine for you when it comes out.

Quick question...

I have a similar issue where I partitioned my SSD on my M1 iMac and rather wish I hadn't (Totally separate partitions, not volumes. An old habit from using previous Macs!). Recovery mode won't now let me remove an unwanted partition.

So my question is - does DFU Recovery wipe all partitions and restore the SSD and my Mac back to how it was fresh out of the box?