Installing Big Sur on a thumb drive

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Installing Big Sur on a thumb drive

Is this possible at all?

I found just one other thread about this, but that poster's issue is not the same as mine, and the poster actually did not get an answer to the question.

I am not upgrading from Mojave. I want Big Sur on an external location just to see what it's like. I will not be transferring any data.

I want to install to a thumb drive for the following reasons:

I want to take up minimal space.
I have a thumb drive with sufficient space, so I do not want to buy an external drive.
I do not plan on keeping the installation connected. I'll plug whatever in when I need it.

But the installer says the drive cannot be used, but doesn't give me a reason why. It is formatted with a GUID partition map.

Mac mini 2018 or later

Posted on Dec 31, 2020 9:26 AM

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Answer 1

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dialabrain

Level 10

125,615 points

Jan 2, 2021 10:43 AM in response to snowshed

FWIW, after seeing your post yesterday, I tried installing Big Sur to a 128GB SanDisk thumb drive. It seemed like it was going to install but, it froze at one minute left for about an hour. Installing to a thumb drive is not looking good.

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Answer 2

Dec 31, 2020 9:39 AM in response to snowshed

If it will install at all on a USB stick, it would have to be 64 GB or larger due to huge size of the unpacked Big Sur installer and its temporary storage requirements. This may no longer be supported too, and only the macOS product team would know for certain — other than repeated failures.

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Answer 3

snowshed Author

Level 1

9 points

Dec 31, 2020 11:49 AM in response to DaveGarratt

Hi, Dave,

You could clone you current HD and make a bootable copy using Carbon Copy Cloner - but it would need an external device with the same or greater amount of space that you use on you live disk.

I started to write a reply, but as I wrote it, I began to wonder if you fully understand the goal.

I want a clean install on a thumb drive, so the initial boot from the thumb drive will be like booting a brand new computer out of the box.

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Answer 4

snowshed Author

Level 1

9 points

Jan 2, 2021 10:38 AM in response to DaveGarratt

This in an Intel based Mac, Mini 2018, and I currently have a clean Mojave install on an external Hybrid drive, and Catalina on a physically small external SSD.

I'm thinking the issue is the fact it's a thumb drive, but why would that be the issue? Size maybe? It's 2 TB. The installer just won't let me select the thumb drive as an install location.

For now, I'm giving up on a thumb drive. LOL I've ordered a 128 GB drive like the one I have Catalina on. The advantage of these 2 drives is it comes with a cable that will plug into a Thunderbolt port.

I may buy a 128 GB thumb drive at Walmart one of these days, and see what happens. If it doesn't work, I'll have a thumb drive that's far, far, bigger in storage capacity than I'll ever need.

Except in the case where I bought a 256 GB drive, just to be sure it was going to be big enough, and I'm using it on a Window mini computer, to have a dual boot W10/Mint 20 system. The Linux install is on the thumb drive.

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Answer 5

snowshed Author

Level 1

9 points

Jan 2, 2021 11:05 AM in response to dialabrain

dialabrain wrote:

FWIW, after seeing your post yesterday, I tried installing Big Sur to a 128GB SanDisk thumb drive. It seemed like it was going to install but, it froze at one minute left for about an hour. Installing to a thumb drive is not looking good.

Thanks for letting me know. I'll skip buying a thumb drive just to give it a try.

After looking at the size of my Catalina install, I'm 99% sure the 129 GB drive will be big enough. I don'w plan on switching to Big Sur as I've bot 32 bit software that's no longer available.

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Answer 6

Dec 31, 2020 11:20 AM in response to snowshed

You could clone you current HD and make a bootable copy using Carbon Copy Cloner - but it would need an external device with the same or greater amount of space that you use on you live disk.

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