Big Sur Volumes on Catalina

[haralds]

I am scratching my head about Apple's sloppy approach of the Big Sur volume appearance on Catalina. It would not have taken much to make the system appear seamless for multi boot. But it also appears to be inconsistent.
I installed by adding a Big Sur volume to a container already containing one or more macOS installations such as Catalina, Mojave, and High Sierra. We do development and need to boot natively to fully test peripheral hardware.
The Update volume is hidden but appears on older Finders. That can be fixed with 'sudo Setfile -a V /Volumes/Update';killall Finder" But why should I have to do it? Big Sur was in mid beta by the time Catalina 10.14.6 was released.
Now the weird part. On my "unsupported" Mac Pro 5,1 the Big Sur volume appears totally normal using the same installation technique as on my MacBook Pro.
On the MacBook Pro 2018 the Big Sur system volume is not recognized (just a disk/slice in Disk Utility.) Big Sur - Data is mounted, but does not show on the desktop.
Why the difference? I went as far as wiping and removing all Big Sur partitions on the MacBook Pro and starting over thinking it might be the Beta 6 installer. No dice.
Sloppy in my view.

 

[gilby101]

Sadly, you made a mistake by installing into the same container. The clear advice from developers/testers is to install different versions of macOS to different containers (better still different disks). This is because newer versions of APFS are not fully supported by older versions. You will continue to see inconsistencies unless you start again with separate containers. Backward compatibility has never been important to Apple.

 

[haralds]

Sadly, you made a mistake by installing into the same container. The clear advice from developers/testers is to install different versions of macOS to different containers (better still different disks). This is because newer versions of APFS are not fully supported by older versions. You will continue to see inconsistencies unless you start again with separate containers. Backward compatibility has never been important to Apple.

I have a standalone installation on a separate disk that show up the same way - Update is visible, Big Sur - Data is mounted but not visible, the Big Sur system volume cannot be read.
Actually I also installed into a volume shared with Mojave and another separate "Shared Data" volume. That one shows up as if it was Catalina. Go figure.

 

[fontman]

I have a standalone installation on a separate disk that show up the same way - Update is visible, Big Sur - Data is mounted but not visible, the Big Sur system volume cannot be read.
Actually I also installed into a volume shared with Mojave and another separate "Shared Data" volume. That one shows up as if it was Catalina. Go figure.

I Have the Same Issues crazy