installing Monterey in separate APFS volume?

In past years I've had a spare Mac I could use but that Mac can't run Monterey so I'd like to install Monterey on a separate APFS volume on my M1 MacBook Pro. I've read the instructions here:

https://support.apple.com/en-us/HT208891

but I want to be certain I don't causes issues with the Big Sur installation. Obviously after backing up, I use DiskUtility to create a new APFS Volume.

If I download the macOSBetaDeveloperUtility.dmg and install it, then I think it will give me the option to update the OS (as that's what I did in the past, but it's not what I want to do this year). From screenshots here:

https://support.apple.com/en-us/HT208891

I think it will allow me to choose where to install and I can choose the new APFS volume I made for the beta. Is that correct?

And then after the installation, will the Big Sur volume work as before or will software update in it want to update to the Monterey beta instead of letting me do any Big Sur updates that come out this summer?

And then at some point after the official Monterey release, I assume I can just delete the APFS volume I created for Monterey to test my apps and then update the Big Sur volume to the official version of Monterey?

Are there any mistakes in my steps/plans?

Thanks, Dave

Accepted Reply

You've presented a good plan for handling the temporary install of the macOS Monterey beta. You will download the Monterey beta installer to your Big Sur volume. You will then use the Monterey Installer to install macOS Monterey to the 2nd volume. The Big Sur volume will remain untouched. You will want to use the Monterey Installer on the Big Sur volume to un-enroll that volume for future Monterey updates - or use the Software Updates System Control Panel on Big Sur to return back to the Production update track.

After the Monterey beta period is over, you can use Disk Utility to re-collect the beta Monterey volume from Big Sur to reclaim the space.

rich kubota developer technical support CoreOS/Hardware/MFI

Replies

You've presented a good plan for handling the temporary install of the macOS Monterey beta. You will download the Monterey beta installer to your Big Sur volume. You will then use the Monterey Installer to install macOS Monterey to the 2nd volume. The Big Sur volume will remain untouched. You will want to use the Monterey Installer on the Big Sur volume to un-enroll that volume for future Monterey updates - or use the Software Updates System Control Panel on Big Sur to return back to the Production update track.

After the Monterey beta period is over, you can use Disk Utility to re-collect the beta Monterey volume from Big Sur to reclaim the space.

rich kubota developer technical support CoreOS/Hardware/MFI

Thanks Rich. It sounds like my understanding is correct other than I need the step at the end when booted into Big Sur to remove the beta profile. I'll give it a try soon when I have time.

Note: Profile installation has to be done on the current volume

Profile installation

  1. Download macOS beta profile from the developer portal
  2. Install the beta profile on your existing volume (this can’t be installed on the new volume)

Download macOS Beta

  1. System Preferences > Software Update now will show the macOS beta
  2. Tap on Upgrade now
  3. Downloading of the macOS beta will start

Create a separate Volume

https://support.apple.com/en-us/HT208891

  1. Open Disk Utility
  2. Select Macintosh HD (top most item)
  3. Add a new volume (no need to allocate any space)

Remove Profile from existing volume

This is required so that macOS beta updates don’t appear on your current volume, otherwise might end up accidentally updating to macOS beta on your current volume

https://beta.apple.com/sp/betaprogram/unenroll

  1. Open System Preferences > Software Update
  2. Click Details > Restore Defaults

Installing macOS Beta

  1. The macOS Beta installer would ask for the location / volume
  2. Tap on show all disks to make all volumes visible
  3. Select the volume you newly created
  4. Install

I don't have Rosetta installed, so I also needed this tip from u/GetVladimir - https://www.reddit.com/r/MacOSBeta/comments/mv2vn8/psa_to_enroll_to_the_macos_big_sur_public_beta/

  • PSA: To enroll to the macOS Big Sur Public Beta without the need to install Rosetta, use "sudo /System/Library/PrivateFrameworks/Seeding.framework/Versions/A/Resources/seedutil enroll PublicSeed"