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MacBook Pro freezes reinstall

help MacBook Pro freezes up during two stall

MacBook Pro

Posted on Sep 26, 2022 10:25 AM

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Posted on Sep 27, 2022 9:28 AM

You may need to use Internet Recovery instead:


How to reinstall macOS - Apple Support


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4 replies

Sep 26, 2022 11:00 AM in response to Grant Bennet-Alder

Install process — rough timetable:


Start download from Mac App Store. This takes 20 minutes to an hour.

Once complete, Installer usually starts. You specify disk on which to Install. [in Recovery, you may sometimes specify the drive FIRST.]


Install checks things out and then copies 6GB or more "MacOS Base System" to the destination drive. [In Recovery, "MacOS Base System" may be downloaded directly onto the specified drive.] Copy time is about 20 minutes to as much as 3/4 hour if your drive is slow. [if installing on the same drive as the download, this step becomes nearly trivial, and does not take any substantial amount of time.]


Installer sets startup to the newly-placed MacOS Base System (as if it were a disk) and does a Restart.

>> a failure right here means you still have everything on your old drive, (plus 6GB of MacOS Base system that does not work)

ONLY if Restart was successful do you begin replacing files to move to the new version of macOS. Time 30 minutes to 3/4 hour.

Restart again and comes up running the new version, in Setup Assistant. This is your best opportunity to bring over your Accounts and data from an other Mac or a backup, if you are changing drives or changing Macs. You can use Migration Assistant later, but it is more complex.


————

It is fascinating to me that the only version that can install a new Major version is... itself!

This eliminates so many cross-version installation issues, but means it is crucial that you are able to “set startup” to the incoming MacOS base system.


Firmware installation (if required) works in a similar way, pre-positioning the firmware installer tiny system, set startup to the tiny system, then restarting.


If you break the chain or can’t install the firmware, the process stops, but does not leave your Mac paralyzed.

MacBook Pro freezes reinstall

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