Trouble reinstalling macOS (Don't erase your disk!)

[AppleFan22]

TL;DR: Don't erase M1 disk, it may cause macOS install errors. More information later.

Got my M1 MBA earlier, booted it to play around with it but now I'm trying to restore it from a backup of my old/current MBP.

I didn't think Time Machine would erase the destination disk, so I erased it from the new macOS Utilities (hold power button until Utilities appears) Disk Utility, and then tried to restore from backup using macOS Utilities. It then told me I had to do this through Migration Assistant (oops) so I tried reinstalling macOS.

Big Sur is a FAT update, so it was taking ages to download with an ethernet cable plugged in, but it kept failing, saying it couldn't personalize the update. Just spoken to Apple Support and they've advised Internet Recovery (which is still Cmd+Opt+R, bizarrely).

It's currently downloading as of now, but it's getting close to the point it was failing before, so I'm not sure what will happen.

I'll post an update when I know more, but for now, it's looking like it's a bad idea to erase your M1 disk!

 

[AppleFan22]

UPDATE 1: Internet recovery failed too, going back to Apple Support.

 

[AppleFeller]

Dang smh I noticed my Big Sur 11.0.1 update seems stuck preparing and was in recovery for a second. I didn't know internet recovery was an option for Apple Silicon still. I wanna give it shot tbh.

 

[AppleFan22]

Dang smh I noticed my Big Sur 11.0.1 update seems stuck preparing and was in recovery for a second. I didn't know internet recovery was an option for Apple Silicon still. I wanna give it shot tbh.

It is, but be careful, it seems it’s locking the firmware, and there is a guide to fix it for macs with T2 chips, but the M1 macs don’t have this, so it won’t work.

 

[AppleFeller]

It is, but be careful, it seems it’s locking the firmware, and there is a guide to fix it for macs with T2 chips, but the M1 macs don’t have this, so it won’t work.

Best of luck, my Big Sur update went through, it was just oddly slow...working great now.

 

[arn]

Try fix listed here

M1 Mini - An error occurred preparing the update

So received M1 Mini today, all installed okay, including Big Sur latest update. Then realised I had put wrong login short name, so decided to do a reinstall rather than mess around renaming accounts. Restarted in 'new' recovery mode, removed existing partition and created APFS new one...

forums.macrumors.com

Revive or restore a Mac with Apple silicon using Apple Configurator 2

In rare circumstances, Apple computers become unresponsive and the chip’s firmware must be revived or restored.

support.apple.com

 

[AppleFan22]

UPDATE 2: Spoken to Senior Support Adviser, we think the update file hasn't been modified to contain M1 data. Trying a bootable USB now, see if that works.

 

[AppleFan22]

Try fix listed here

M1 Mini - An error occurred preparing the update

So received M1 Mini today, all installed okay, including Big Sur latest update. Then realised I had put wrong login short name, so decided to do a reinstall rather than mess around renaming accounts. Restarted in 'new' recovery mode, removed existing partition and created APFS new one...

forums.macrumors.com

Revive or restore a Mac with Apple silicon using Apple Configurator 2

In rare circumstances, Apple computers become unresponsive and the chip’s firmware must be revived or restored.

support.apple.com

Will try this next, thanks!

 

[AppleFan22]

Couldn’t give an update last night as I got too tired of messing around with it. Configurator didn’t work, it seems like I can’t get it to go into DFU mode (???), so I think I may be fresh out of options.