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External SSD Boot Drive

I am running my MacMini successfully from an external SSD boot drive. It boots at startup without any problems. However, when I do updates, or try to upgrade the OS the update fails when the Mac restarts during the update. The restart fails and reverts to the grey utilities screen. When I select the external drive to restart it does a fresh restart without the update. Any suggestions?

Mac mini, macOS 10.14

Posted on Dec 27, 2021 8:03 AM

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Question marked as Top-ranking reply

Posted on Dec 28, 2021 6:31 AM

Hyper-focal wrote:

I don't think the issue is with finding the startup disk as it seems to be getting this far. The installer log suggests there are some missing files.

Reinstall macOS Mojave over the top of the current macOS Mojave version on the SSD.

https://support.apple.com/en-us/HT204904

I'm trying to upgrade to Monterey, but this issue is causing me the problem.

Then try and upgrade to Monterey.

https://support.apple.com/en-us/HT212735

Similar questions

9 replies
Question marked as Top-ranking reply

Dec 28, 2021 6:31 AM in response to Hyper-focal

Hyper-focal wrote:

I don't think the issue is with finding the startup disk as it seems to be getting this far. The installer log suggests there are some missing files.

Reinstall macOS Mojave over the top of the current macOS Mojave version on the SSD.

https://support.apple.com/en-us/HT204904

I'm trying to upgrade to Monterey, but this issue is causing me the problem.

Then try and upgrade to Monterey.

https://support.apple.com/en-us/HT212735

Dec 28, 2021 4:02 AM in response to Hyper-focal

Follow these Apple Support steps to change your startup disk: Change your Mac startup disk - Apple Support, specifically this section:

Change your startup disk for every startup
On your Mac, choose Apple menu  > System Preferences, then click Startup Disk .
If the lock at the bottom left is locked , click it to unlock the preference pane.
Click the icon of the disk you want to use, then click Restart.

Cheers,


Jack

Dec 28, 2021 4:17 AM in response to Hyper-focal

Thanks for confirming.


Please Reset NVRAM or PRAM on your Mac - Apple Support, then Change your Mac startup disk - Apple Support again. In addition, please let us know what external SSD you are using.


Also, is there a reason you are still using macOS Mojave on your Mac mini (Late 2014)? It supports macOS Monterey, and I regularly use a Mac mini (Late 2014) using macOS Monterey that has an external SSD as its startup disk with no issues.


Jack

Dec 28, 2021 9:17 AM in response to Hyper-focal

You're welcome.


Yea' that should actually be faster, easier and work better than trying to reinstall Mojave, then upgrade to Monterey..


While I would not freely recommend it to the average or below average user because of the potential data loss and other problems. I'm glad to hear that you are setup, willing and able to go this route.

External SSD Boot Drive

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