CCC 5.1.23+ can make bootable backups of Big Sur on Intel-based Macs.
Update Nov 24: CCC 5.1.23 can now make bootable backups of a Big Sur startup disk on Intel-based Macs. Support for System volume cloning on Apple Silicon Macs is disabled for now because Apple's APFS replication utility does not currently work on that platform. When Apple fixes that, we'll post an update to CCC that restores support for making bootable backups on Apple Silicon Macs.
CCC is a native application on Apple Silicon and is 100% compatible with Apple Silicon Macs
CCC will automatically proceed with a Data Volume backup when backing up an APFS Volume Group on Apple Silicon Macs — that's a complete backup of your data, applications, and system settings. If you would like to make your Apple Silicon Mac backup bootable, you can install Big Sur onto the CCC Data Volume backup. Please keep in mind, however, that your CCC backup does not have to be bootable for you to be able to restore data from it.
With the announcement of macOS Big Sur, Apple has retired Mac OS X (10) and replaced it with macOS 11. As with every upgrade since the original release of Mac OS X, we have to make changes to CCC to accommodate the changes in this new OS. As the numeric change would suggest, though, this is the biggest change to macOS since Apple introduced Mac OS X roughly 20 years ago. The system now resides on a "Signed System Volume". This volume is cryptographically sealed, and that seal can only be applied by Apple; ordinary copies of the System volume are non-bootable without Apple's seal. To create a functional copy of the macOS 11 System volume, we have to use an Apple tool to copy the system, or install macOS onto the backup.
Does this mean that we can no longer have bootable backups?
I can certainly understand why people are concerned about the future of this solution. Thanks to these massive system changes and some bugs in the version of Big Sur that Apple intends to ship, nobody can make a proper copy of the System volume right now, not even with Apple's proprietary utilities. Based on that statement alone, and a suggestion from one of my competitors to just give up and use Time Machine instead (which does not make bootable backups, nor back up the System), someone could falsely conclude that it's impossible to have a bootable backup.
I think that pessimistic conclusions are also fostered by a concern that Apple is trying to turn macOS into iOS, or otherwise merge the two... Read More