How to Clean Install MacOS Catalina. Because the Mac was erased during this process, there will be no personal files, no apps, no preferences, no settings, no customizations whatsoever on the Mac, it will be as if it is new, which is why this is colloquially called a “clean install” in the tech world. First step: Create an installation ISO. The easiest installer to build is a recovery image, which will download Catalina during installation. Download and run fetch-macOS.py in a terminal to download the Catalina recovery image from the Apple software distribution server (this can be run on Linux, Proxmox, or on a Mac): This results in a 500MB.
Installing Macos Catalina Stuck
Installing Macos Catalina On External Drive
I’m trying to install Catalina on an empty external 500gb SSD, formatted APFS. My Mac is also running Catalina. I went to the App Store and fetched a copy of the installer, which is now sitting in my Applications folder, all 8gb of it.
I start the installer, point it at my external SSD, and it starts chugging, looking all OK. The progress meter says 5 minutes. After around that time, with nothing unusual reported, the screen goes black and the restart sequence begins. But it restarts from my internal disk and the new installation is not complete.
Second attempt, I followed instructions to create a bootable USB installation disk on another USB drive, booted to it and started the installation from there. Same result.
Any suggestions?
I start the installer, point it at my external SSD, and it starts chugging, looking all OK. The progress meter says 5 minutes. After around that time, with nothing unusual reported, the screen goes black and the restart sequence begins. But it restarts from my internal disk and the new installation is not complete.
Second attempt, I followed instructions to create a bootable USB installation disk on another USB drive, booted to it and started the installation from there. Same result.
Any suggestions?