My mac is using Catalina, I was following the link installing macOS Beta on a separate APFS volume to install
Sponsored by Logitech: Get the MX Master 3, MX Keys, and K380 for Mac today! In the current macOS Big Sur 11 developer beta. Of course, you still need to have the needed free storage space on your Mac as a whole to contain the new macOS version. For Macs with APFS file system, Apple recommends creating a new volume within your current partition when attempting to install a separate macOS version in addition to your current one. Open diskutil, click on view, show all devices, then go to your very top level ssd and click partition and make sure it’s APFS, then after it’s done it should look something like this. Just verify that the beta volume is on a seperate APFS File container than your catalina and you’re good. Continue this thread. Now, select the topmost line on the left (the physical drive) 4. Click the ERASE button - choose APFS with GUID partition format. Now, erase the drive. REMEMBER - this WIPES OUT all data on the drive. IF you can get that far, now close disk utility and open the OS installer. See if you can install a copy of the OS now. I’m currently running Catalina, but need to install Mojave on a separate volume on my hard drive in order to run some 32-bit apps. Following directions in a Macworld article that purports to show how to do this, I created an APFS volume and named it Mojave. The article then said to download the desired installer.
Big Sur Beta. After installation completed, I switch back to Catalina, I found the developer app installed on Catalina won't work, it crashes immediate when I open it.
I tried to delete the volume that installed Big Sur Beta, but it's not working, I am still not able to open developer app. Further more, on Catalina OS Volume, there are two new volume was created:
Volume with name update appears on desktop, I have no idea what it is.
Volume with name disk1s7 appears on disk untilites, I cannot erase it, I cannot delete it.
The question is, how to completed remove beta OS from separate APFS volume with the volume update and disk1s7?