Mac OS Big Sur won't finish install

Portable SSD Portable | Extreme | Extreme Pro SSD
1

I use an extreme pro 256 as my boot volume for an iMac late 2015. I am currently running Catalina from it. I upgraded the internal hard drive to Big Sur successfully. But when I try to install Big Sur on the extreme pro, the install does not complete. On final restart, the install gets stuck with an apple logo and a progress bar at about 40%. I left it like that for hours, I tried multiple restarts, but I could not get it to work. I have another external hard drive from which I was able to downgrade back to Catalina successfully.

Has anyone been able to install Big Sur on the Extreme Pro SSD 256 and run your Mac from it? Any tips to get it to work?

2

Have you sorted this out?

3

It sounds like you failed to create a bootable macOS Big Sur USB installer.

Can you recall where you downloaded the macOS Big Sur installer from? If you need, download the full installer again.

The steps of creating a bootable installer are lengthy and require some tech knowledge of using Terminal command:

If you want to save the hassle of creating a bootable installer, third-party apps would be of help. Related walkthrough blog: Mac OS Big Sur Download: DMG, ISO, Full Installer [Direct Links]

4

I didn’t ever get this to work out. I was able to create a Linux bootable installation and run Linux on the MacBook. But I have passed all the hardware on.