Strange partition after upgradeding to Big Sur

[Quackers]

@corentin-p TM backup wouldn't run because there were 2 volumes with the same name. Not surprising really.
So I used your command to delete the volume and it ran ok.
I'll boot into Catalina later and check it out.
I'm currently running a TM backup (fine now).
Will this TM backup back up everything? Catalina, Big Sur, EFI etc etc and so be usable to restore both systems or is that hoping too much? 🙂
I've not used TM much as previously I've used cloning programmes.

 

[Quackers]

Ok all done.
Booting back into Catalina I find that the only thing that appears wrong is that my Pictures folder won't open because the original file can't be found. That's not a big thing so I think I'll just delete the folder and create another folder with the same name and fill it up with what I can replace.
If anything else, more serious fails I'll just re-install.

 

[corentin-p]

@corentin-p TM backup wouldn't run because there were 2 volumes with the same name. Not surprising really.
So I used your command to delete the volume and it ran ok.
I'll boot into Catalina later and check it out.
I'm currently running a TM backup (fine now).
Will this TM backup back up everything? Catalina, Big Sur, EFI etc etc and so be usable to restore both systems or is that hoping too much? 🙂
I've not used TM much as previously I've used cloning programmes.

I would say no, if the volume is not mounted and the OS on it not booted I think it will not back it up. I may be wrong though, but I wouldn’t count on it.

For your photos, that is strange, Photos.app may have its library still pointing to a file in the old volume, but I cannot see how that would happen when reinstalling the OS. or Are you talking about the Pictures Folder in Finder ? In that case something even more strange happened (OS still pointing to the old « - Data » volume, but just for Pictures ? ) from Catalina onwards, the Finder is basically lying to you and presenting the two volumes in a volume group as one. But if everything else was kept when deleting the volume - wallpaper, apps prefs, etc, then the linked volume was the right one, so I don’t understand.


Corentin

 

[Heat_Fan89]

Same here on clean install. I think this is related to the the new crypto signing on Big Sur for extra protection. Below is from Apple

"Signed system volume​

In macOS Catalina, Apple introduced the read-only system volume, which is a dedicated, isolated volume for system content. Now, macOS Big Sur adds strong cryptographic protections to store system content on a signed system volume (SSV). SSV features a kernel mechanism that verifies the integrity of the system content at runtime, and rejects any data — code and non-code — that doesn’t have a valid cryptographic signature from Apple.
SSV helps prevent tampering with any Apple software that is part of the operating system. Additionally, it makes macOS Software Update more reliable and much safer. SSV utilizes APFS snapshots, so if an update cannot be performed, the old system version can be restored without reinstallation."

Different approach but that kinda sounds like what Microsoft does with Windows. They create file hard links on the disk drive as added protection for the OS. In Windows it's the WinSxS folder which at times can grow larger than the actual OS itself. And recently with Windows 10 they too created an 8GB partition for updates and recovery as well as caching.

The new Big Sur partition doesn't really bother me at all as long as it makes the OS more stable, I'm all for it. It's no biggie for me.

 

[corentin-p]

Different approach but that kinda sounds like what Microsoft does with Windows. They create file hard links on the disk drive as added protection for the OS. In Windows it's the WinSxS folder which at times can grow larger than the actual OS itself. And recently with Windows 10 they too created an 8GB partition for updates and recovery as well as caching.

The new Big Sur partition doesn't really bother me at all as long as it makes the OS more stable, I'm all for it. It's no biggie for me.

except with windows you don’t risk rendering the boot volume unbootable if you modify, let’s say, the resource\themes folder in c:\windows from another system. Updates may fail though.

and the tools to repair an online windows image are known : dism /cleanupimage , sfc /scannow.

system integrity checks are good for security, but we lack a set of well documented tools to scan and repair if integrity is defeated. If that happens right now, you’re left with an unbootable system or at best a non upgradable system. And in my opinion it’s a first step towards a non-modifiable system partition. No more exotic drivers / kext that only run from S/L/E, back ports of old programs, etc.

I guess this is the way all OSes go now. Microsoft would have done it a long time ago if it didn’t need to run on so many hardware configs.

 

[mmgrossmann]

After I had upgraded to MacOS Big Sur in this morning I saw a strange partition in disk utility with a name "com.apple.os.update-77..." , see picture.

Is this a normal partition or is it just me?

View attachment 1663486

I don't have this problem, but I have another one.
I use a MacBook late 2016.

Time Machine does not seem to know what disk needs to be backed up. When I connect an external drive, it thinks it is what I want to back up and I cannot change this.
Also the application "System Information" which was in Utilities doesn't seem to work anymore. I guess it was deprecated, which is unfortunate, because we do not get the same level of system detail looking at Apple > About this Mac.

 

[Quackers]

I don't have this problem, but I have another one.
I use a MacBook late 2016.

Time Machine does not seem to know what disk needs to be backed up. When I connect an external drive, it thinks it is what I want to back up and I cannot change this.
Also the application "System Information" which was in Utilities doesn't seem to work anymore. I guess it was deprecated, which is unfortunate, because we do not get the same level of system detail looking at Apple > About this Mac.

I had a similarly named partition but that changed after a couple of boots and a backup to just "Update"
You should be able to exclude the external drive from the TM backup (TM Preferences - Options).
Not tried system information to be honest but Apple - About this mac - System report still works here.
Might be useful to you.

 

[Quackers]

Actually System information in Utilities still works here.

 

[Heat_Fan89]

And in my opinion it’s a first step towards a non-modifiable system partition.

I see this also as a first step towards making the Mac platform much like iOS and iPadOS. System updates will be signed by Apple and once they stop signing them you won't be able to go back. I'm just getting that concerned feeling with the inclusion of the T2 chip, later adding Apple Silicon chips followed by an iOS dress down of the UI. I hope i'm 100% wrong and way off on my conspiracy theory.

 

[w1z]

Hi w1z

Thank you for that info, but do you have any official apple info supporting that ? Just curious, and trying to understand what that line means.

Also, how is it possible that my seal is broken on a fresh Big Sur install (again, I used Internet Recovery, deleted « Macintosh HD » and « Macintosh HD - Data » volumes, erased APFS container, recreated an APFS container to reinstall - did I do something wrong ?) ?

Quoting https://eclecticlight.co/2020/06/25/big-surs-signed-system-volume-added-security-protection/

The seal is verified each time your Mac starts up, by the boot loader before the kernel is loaded, and during installation and update of macOS system files. If verification fails, startup is halted and the user prompted to re-install macOS before proceeding.

Do you have Apple Secure Boot disabled? If so, re-enable it and attempt another installation.

 

[corentin-p]

@w1z thanks for the suggestion,

I just booted back in recovery to check, secure boot is on « maximum security » and does not allow booting from external volumes. I did not mess with these settings so it was already like that during my internet recovery install of Big Sur.

I guess 11.0.2 or 11.1 will be decisive. If I do not manage to update, I’ll know why.

I have no warnings during boot and the snapshot the system uses to boot - is - sealed so maybe this is just normal.

csrutil status reports « enabled » and I did not disable it on this setup.

SOS ran from disk utility in recovery on « MacHD » said « the volume /dev/rdisk3s5 appears to be OK. » I’m not too worried, will report back if the first update available can’t be installed.

Corentin

 

[kkinto]

Not sure how all this stuff above computes and relates yet but I also have a very strange arrangement of drives on Big Sur (unsupported Mac Pro) - On my desktop there is an icon named "Big Sur" which seems to all intents and purposes as the HD. But in Terminal DiskUtil and DiskUtility its very weird (see screenshot).

All would have been fine except for some reason I have lost USB on input devices (keyboard / mouse) and if I hard restart my Mac boots into Mojave (on another HD) and Big Sur is nowhere to be found. No option on desktop or Startup Disk. In Disk Utility there was only a single a greyed out volume "disk3s6" that could not be mounted on the SSD that Big Sur was installed on. Only the other APFS volume 'Skritch' appeared properly (and was mounted).

When restarting in Catalina (I have all 3 installed), all seems fine except for no Big Sur. Took a few restarts in Catalina and then suddenly there is the disk "Untitled" mounted - and also appearing in Startup Disk choices, which when chosen and restart booted Big Sur. I have no idea wtf is going on but its certainly a sign of something amiss here!

 

[tkermit]

Something else struck me : the snapshot is marked 'Snapshot sealed : yes' but the original Big Sur 'System' Partition is marked 'Sealed : broken'.

That's normal

Is Big Sur’s system volume sealed?

How can you tell whether your Mac’s shiny new Sealed System Volume is properly sealed? You could easily be misled into thinking it isn’t.

eclecticlight.co

 

[Quackers]

Mine's exactly the same.

 

[corentin-p]

thanks @tkermit

corentin@MBA-Orcitenn ~ % csrutil authenticated-root status
Authenticated Root status: enabled

I'm all reassured now 🙂

 

[corentin-p]

Hey Guys and gals, just a quick heads up after 11.1 update, even if we were, I guess, already convinced this was normal, but : everything is fine, the new snapshot is still sealed, and the original volume's seal is still in 'Broken' state.

Have a great and safe holiday all.

Corentin