M1 Big Sur 11.1 Clean Install with formatting SSD thread

[dengue]

Hello.
With 11.1 update, I would like to do a clean install with erasing and reformatting ssd and setting up like new my MBA M1.

If someone already did it, please explain in steps how to do this without bricking device.

And I want to do a clean install of 11.1, not installing 11.0.1 and updating to 11.1 again. As I see on apple support page, there is only possibility to install to Big Sur version that comes with Mac (it was 11.0.1)

Can I just boot into recovery, erase and format, and download from internet recovery 11.1? it will be perfect. Thank you

 

[anubis1980]

Hi, yes it works fine on my MBA M1

I just rebooted into recovery , clicked the erase Mac option , reinstalled Mac OS and all worked fine. Took about an hour for me. Sorry I can't remember the exact steps I did to write it out but I did the same 2 weeks ago and took me 5 hours of trying to fix it as had so many errors. This time was very smooth sailing

 

[dengue]

Hi, yes it works fine on my MBA M1

I just rebooted into recovery , clicked the erase Mac option , reinstalled Mac OS and all worked fine. Took about an hour for me. Sorry I can't remember the exact steps I did to write it out but I did the same 2 weeks ago and took me 5 hours of trying to fix it as had so many errors. This time was very smooth sailing

thanks, did it install 11.1 or 11.0.1 on your machine?

 

[anubis1980]

it installed 11.1

 

[downshiftdre]

I already updated to 11.1. Could I still do this reforma/clean install? Some additional detailed stepin particular the recovery portion on whether to do a mac recovery or an internet recovery would help. Thanks.

 

[anubis1980]

I had updated to 11.1 beforehand and wiping it after worked fine. Sorry I am a pc user normally so I tend to bumble along in osx. I know I just went into recovery mode , wiped all the disks and clicked on the reinstall macOS bit. worked fine.Hopefully someone else can give a better detailed description.

 

[enneen]

Please read this thread.
Looking to reformat or erase your M1 Mac?
And carefully follow the steps and you will be fine. It's a very easy and well explained process.

 

[rmgbenschop]

I used this link to reinstall my Mac with success.

The first time I erased the SSD of my Mac to do a clean install I wasn't aware of the extra steps on this particular model. With all my Macs I did the same thing: create a bootable usb drive with the MacOS software on it, boot from it, erase the disk and install MacOS.

Now you need to activate the Mac first before you can use the bootable usb drive (or like @anubis1980 you can use the Recovery Toolkit that downloads and installs the latest MacOS) which is all decribed in the link from Apple Support.

 

[macnmac]

if you did a clean install for 11.0.1 and updated to 11.1, is it still a clean install or do you need to format each time an update comes out?

 

[dengue]

I did a clean install, and everything seems work ok, but is it normal in disk utility? Why don't just showing Macintosh?

 

[Rob9874]

I'd like to do this as well. Wondering if anyone else can confirm this is as easy as stated in OP, and not the issues I read about when the M1's first came out.

 

[Gnattu]

I did a clean install, and everything seems work ok, but is it normal in disk utility? Why don't just showing Macintosh?
View attachment 1694809

Because Big Sur does not boot from the filesystem directly, it creates a snapshot and then boot from that (read only) snapshot, the com.apple.os.update-xxxx is the name of that snapshot. The snapshot process is part of the the new security feature called Signed System Volume introduced in Big Sur. Each time a system update is performed, instead of modifying the filesystem directly, a new snapshot is created and the system will boot from that new snapshot instead.

 

[honestone33]

Because Big Sur does not boot from the filesystem directly, it creates a snapshot and then boot from that (read only) snapshot, the com.apple.os.update-xxxx is the name of that snapshot. The snapshot process is part of the the new security feature called Signed System Volume introduced in Big Sur. Each time a system update is performed, instead of modifying the filesystem directly, a new snapshot is created and the system will boot from that new snapshot instead.

Yes, I see exactly that on the partition for my Samsung T7 1TB SSD onto which I did a clean installation of V11.1 yesterday.

 

[Bending Pixels]

Question - under Catalina, If I wanted to do a clean install, after booting into macOS Recovery, I would go into Disk Utility and delete the volume Macintosh HD (contained separate partitions for the system and Data), erase with naming the SSD ‘Macintosh HD’, and then reinstall macOS Catalina. Will this method still work?

 

[honestone33]

Question - under Catalina, If I wanted to do a clean install, after booting into macOS Recovery, I would go into Disk Utility and delete the volume Macintosh HD (contained separate partitions for the system and Data), erase with naming the SSD ‘Macintosh HD’, and then reinstall macOS Catalina. Will this method still work?

One would think so. But this is Big Sur. Not sure if things are the same.

 

[DeanL]

I did it successfully but I restored my Mac using Apple Configurator! Worked like a charm.

 

[bsmr]

I did a clean install, and everything seems work ok, but is it normal in disk utility? Why don't just showing Macintosh?
View attachment 1694809

Looks like mine. Without new install. Got it from apple this way. Looks like it is normal behavior.