Big Sur Installer – final install sequence hangs at 30% through

Question

mr.datsun Author

Level 1

4 points

Big Sur Installer – final install sequence hangs at 30% through

I am installing Big Sur on a USB key. So I can boot off the key without changing my main OS Catalina system.

I have used the Startup Security utility to enable booting from a USB device.

I have downloaded and started the installer and selected the USB key.

The files have been installed on the USB key

Then when the MacBook Pro is rebooted it starts the final installation sequence.

The Process hangs at around 30% of the way through.

I have left it like this for two or three hours. The install bar does not move.

I have repeated the whole process twice and the same result. And after running the installer, I have rebooted the macBook to start the final install three times and the same result.

NB. Please note – I am not trying to make an installer on a USB key, I am trying to run the OS directly from the key.

MacBook Pro 15″, OS X 10.11

Posted on Aug 9, 2021 5:30 AM

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Answer 1

jajoho

Level 1

21 points

Aug 9, 2021 7:02 AM in response to mr.datsun

I don't know how to unmarked it as solved. You could try to click on the arrow down symbol.

Sorry, my mistake. I forgot that you need APFS for Big Sur.

Is your Mac connected to the internet when booting from the USB drive? It is possible that Big Sur needs to download additional files while finishing up the installation.

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Answer 2

Aug 9, 2021 7:03 AM in response to mr.datsun

mr.datsun wrote:

I accidentally clicked 'solved' - how do I change that?

unfortunately, you can't.

but anyways, most USB sticks are insufficient for use as a boot drive. you would be well served to buy an external SSD and use that. i personally prefer the Samsung T7.

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Answer 3

PRP_53

Level 10

91,795 points

Aug 9, 2021 7:12 AM in response to mr.datsun

Not possible.

But the upside is the Solution was found. Anyone else with similar issue should be able to discern the actual solution.

And agree, USB Sticks tend to fail very easily and for not reason. Much better running off an external SSD

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Answer 4

mr.datsun Author

Level 1

4 points

Aug 9, 2021 6:54 AM in response to jajoho

No, because you cannot install Big Sur on a GUID formatted drive. You need to use APFS before you can select it for installation, whatever all the help pages say.

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