Home Forums FineTunedMac Community Lounge First Look At Big Sur

I'm having a LOT of trouble trying to believe that Apple is going to leave us with no way to create a bootable clone. I'm having a LOT of trouble believing that they'd even think of it.

Their mandating an Internet connection for upgrading was bad enough, but at least it only left us potentially unable to upgrade, which is an option rather than a necessity.

How do they expect us to recover when we NEED to recover and we haven't got Internet accessibility?

I hope Artie will forgive my copying his post in another string, but I think it is pertinent in this thread as well.

I have two observations:

1. After Apple went to the trouble of creating the very useful clone command in Catalina, that CCC and TinkerTool System made use of, the fact it does not work in Big Sur would lead me to believe either Apple doesn't know how to make it work with the new constraints or doesn't know how to make it work without creating unacceptable security vulnerabilities. That doesn't mean the issue can't or won't be solved, but it may take a lot of blood, sweat, tears, coffee, late nights, cold pizza, and time to do so. I don't envy the engineering team that has this on their todo list. It may not be at, or even near, the top of that todo list either as I suspect the vast majority of Mac users don't even know what a clone is. 😳
2. You haven't been reading the highway signs marking the road for software updates, upgrades, reinstalls, and application installs. The first obvious road sign was the App Store like iOS. The second, a billboard instead of a sign, was the Recovery Drive. MacOS is tail-end Charlie on this. There are thousands of iPhones and dozens of iPads for every Mac and neither has ever had any way of getting software except the internet or cellular. Bringing MacOS and its distribution channels into line with the other ninety percent of Apple products is inevitable.

I don't know about iPads, but can't iPhones be restored from the backup on your Mac?

And I suspect that those Mac users who are aware of clones are the ones who are the most at risk if they go by the boards.

Neither macOS or the hardware that runs it is infallible, and I think Apple needs to consider that.

Unlikely to happen. Apple has been on this track for years and shows no signs of being diverted (especially if diversion would reduce security one iota).

Maybe adding cellular capability to the MacBook would solve your conundrum.

We're wrapping up our beta testing cycle for macOS "Big Sur" 11. CCC will create Data Volume backups of any Big Sur startup volumes. Apple's APFS replication utility is still not currently capable of replicating a Big Sur System volume (as of Big Sur Beta 8). We're working with Apple to develop the functionality within macOS that will allow third-party backup applications to continue making backups of macOS System volumes. In the meantime, we're making complete backups of your data, and those backups can be seamlessly used alongside the macOS Installer or Migration Assistant to produce a bootable backup or to facilitate a restore

Unfortunately from Apple's perspective that all makes sense. Why clone the System when you can do an Internet Restore and grab the System from on line. Well, I can still think of reasons—like no Internet connection—but Apple does not ask me.

The Health app on my iPhone tracks sleep and knows when I wake up and go to bed.

]Sounds just like Santa Claus!

How about reversing that procedure and cloning your data volume to an external drive that's already got macOS installed on it?

Is the system volume actually MORE untouchable in Big Sur than it is in Catalina, i.e. has it been fixed so it can't be manipulated from a clone as I do in Catalina (like booting into OS 9 to manipulate the early versions of OS X)?

Yes, it's cryptographically sealed and then a snapshot is taken. On startup, the snapshot is mounted and that's what the system boots from – the original System volume isn't even mounted. If you mount the System volume and make changes to it, that renders the system non-bootable. You can learn more about it here:

https://developer.apple.com/news/?id=3xpv8r2m

There is actually a mode in which you could modify the system and create your own snapshots, but that's geared towards kernel extension developers.

Some new (I think) Big Sur details from an exchange with Mike Bombich

Thanks to Mike Bombich for sharing that information....

An interesting idea....

An interesting idea, but sadly one that does not work. I just tried re-cloning the data volume on my bootable Big Sur clone. The cloning process was very quick, but when I attempted to boot the re-cloned drive i kept getting a reversed ⌀ symbol and finally had to quit the process with the power switch. 😖

Ah-well, it was worth a try. I just wish it weren't going to take so long to re-install Big Sur on the drive after I erase it and once again clone the data volume to the drive. 🤷‍♂️ Although I don't really know why I am going to do that as the critical data stores will never be current on the cloned volume. But it is a shame to have such a fast external SSD sitting around unused. 🙅‍♂️

artie: but that you can achieve a bootable volume by combining it with either a Time Machine or Recovery restore

Mike: No, Time Machine isn't required at all. An Internet connection is only required to download the Installer, which you've done already if you've installed Big Sur. Hang on to that Installer – drag it to some other volume to make a copy that the Installer won't delete. When you've finished installing Big Sur, run your CCC backup to get your Data-only backup created, then install Big Sur onto the backup. At that point you have a bootable backup, and presumably a backup of that macOS Installer as well. If Internet connectivity is a problem in your area, then definitely save a copy of the installer. (Addendum: Red text is contradictory, no?)

artie: Can I install Big Sur on an external drive and keep it current by cloning my internal data volume to it regularly?

Mike: CCC will keep the Data-only volume current, yes. Nothing copies the System volume – not CCC, not Time Machine, nothing nor nobody can copy it (yet), not even Apple. The only way to restore the system right now is to reinstall it.

FWIW, I'd wait on this one. There is no impetus to upgrade to Big Sur, and there are some lower-level things that are still not working correctly. The biggest problem right now is that the "Signed System Volume" is supposed to be cryptographically "sealed", but that seal is constantly broken. A volume with a broken seal isn't supposed to be bootable, but Apple has relaxed that requirement because the functionality doesn't work. You're in no worse shape than in Catalina where the volume lacks the seal altogether, but then there's also no advantage (security-wise) to upgrading just yet.

The one thing I'm scratching my head about, and regret not having asked Mike about, is how Migration Assistant is dealing with this, and can it perhaps be used in place of CCC for some necessary functionality?

Finder shenanigans with the Applications folder

Firmlinks are mostly transparent, but there is one really noticeable exception: the Applications folder. The Applications folder at the root level of the System volume is a firmlink to the Applications folder at the root level of the Data volume, however, if you navigate to your startup disk > System > Volumes > Data > Applications, you'll notice that the bulk of the Applications are not there. Yet when you look at the Applications folder on the System volume, they are all there! The Finder applies some magic here. The read-only System Applications folder actually resides at System > Applications on the System volume, and when you open the Applications folder in the Finder, you'll see the aggregation of that folder and the Data volume's root-level Applications folder. To the average user, this is exactly what you expect to see, and that's great. However, you may notice that this same aggregation is not applied to other system volumes that your Mac is not currently booted from (e.g. your backup disk). On those volumes, if you open the root-level Applications folder on the visible System volume, you'll only see the content of the firmlink to the root-level Applications folder on the Data volume (i.e. no Apple applications, just your third-party applications and Safari). Rest assured, though, that all of the applications are backed up! You'll find them at System > Applications on the backup volume.

Migration Assistant only deals with the data volume. It is through the magic of firmlinks that applications installed in the data volume appear in the System volume. Quoting from Mike Bombich's Working with APFS Volume Groups

Note: The file path I've highlighted in red doesn't exist in Catalina, but if you follow the closest thing to it that does exist you see what Mike's talking about, although in reverse.

Mike's response to my question may be "quoted" as "Installing Big Sur on top of a CCC data clone and running Migration Assistant on top of a Big Sur installation yield the same results."