Join Big Sur data partition onto Monterey data partition

[steve123]

I have installed Monterey onto my SSD in the same container as Big Sur. When I boot Monterey, none of the applications from Big Sur appear in the Monterey applications folder. Is there some way to "join" /Applications from Big Sur with /Applications in Monterey? I've looked into synthetic firmlinks but my understanding is this will not "join" the two.

Second, is there a way to configure Monterey to use /Users from the Big Sur data volume? I would prefer to not "migrate" my user account from Big Sur to Monterey. If I move back and forth between the two operating systems, I prefer to use the same user account so I do not have to migrate changes between two separate accounts. Moreover I have about 50GB of iCloud storage and migrating a user duplicates this across both user accounts.

 

[Taz Mangus]

A couple of things that might work for you. As far as the shared user account, open System Preferences->Users & Groups, click on the padlock and unlock it. Right-click on your user, select Advanced Options... In the Home Folder field you can change where your home folder resides. You could point that to share your user account with Big Sur. The only thing you need to be careful of is that the the User ID is the same for both Big Sur and Monterey. If they are not the same then you will run into issues and probably bad side effects. The other thing, the Big Sur Volume will need to be mounted before it can be accessed. You might need to try it and see if the Big Sur Volume mounts when you artenpt to login to your user account in Montrey.

As far as the Applications folder, you clued drag the Big Sur /Applications folder to your user account dock, right-click on it from the dock and View Contents as to List and Display as not Folder. Now when you want to execute a Big Sur application you can do it easily from your dock.

 

[gilby101]

I don't like what you are doing. Mixing BS and Monetary in the same container will be the source of multiple issues down the track. Keep them as far apart as possible! Better to use separate containers and preferably different disks (though that may not be so important on older hardware).

For user folders, don't try to combine - just read what's needed from the other volume. Attempting to use the same ~/Library will be a mess.

Even keeping is separate container or disks....

The only thing you need to be careful of is that the the User ID is the same for both Big Sur and Monterey

Essential to avoid permissions issues.