[bxparks]

Just a quick digression: If you decide to upgrade from Mojave to Big Sur, make sure you create a bootable USB installer first, and back up anything that you don't want to lose. I decided to upgrade because Mojave is no longer getting security updates, but ran into some issues took 2 entire days to resolve.

During the in-situ upgrade process, I probably got hit with this installation bug (https://en.wikipedia.org/wiki/MacOS_Big_Sur#Criticism) where the installer never finishes if you have more than 20,000 folders in an obscure folder. I'll never know because I was forced to wipe the disk and perform a clean install. But before you wipe your disk, do a search for "Macintosh HD - Data" and "Macintosh HD - Data - Data", because the Big Sur installer is apparently not idempotent, so you need to delete the "Macintosh HD - Data" volume if the installer breaks halfway through the process.

You should create the USB installer before all this because the clean install may download the Big Sur image, then throw it away, and proceed to download and install Snow Leopard instead. At least that's what happened to me. But Snow Leopard not have the certificates necessary to connect the App Store. So the machine can't download the Big Sur image anymore. The only way around that is to own a second Mac to download the image and create the bootable USB drive for Big Sur, and do another clean install.

[shuffel]

Thanks bxparks for the heads up! I haven't had a good experience upgrading macOS in the past either. I appreciate all the helpful advice on HN.

[password4321]

https://github.com/acidanthera/OpenCorePkg/tree/master/Utili... can download diagnostic and recovery images.