Mike's picture by Mike | May 19, 2021

We've had so many new features in the oven for a while, and now we're finally ready to share it with the world! CCC 6 offers unprecedented accountability for your backups and insight into what's changing on your Mac, plus a brand new file copier that's faster, smarter, and designed to adapt to Apple's fast pace of OS and filesystem innovation.

Take a look at what's new in CCC 6:

The core CCC backup features you know and love are now better than ever!

Faster backups with our next-generation file copier

We've completely rebuilt our file copier to take advantage of the performance characteristics of modern storage. Built on a multi-threaded design, our new file copier provides a foundation for many of the new features noted below, and paves the way for many new features in the future.

Quick Update: Update your backups up to 20X faster

CCC can now tap into the macOS FSEvents service for a list of folders modified on the source since the last backup rather than scanning every folder for changes. Especially for tasks involving a destination network volume, the performance benefit of this feature cannot be overstated!

Redesigned Interface with Dark Mode

It’s been a while since we’ve given CCC’s interface an update and think you’ll enjoy its sleek new look. CCC’s main window is reorganized to make it smaller while making many of the controls and font sizes larger. We completely redesigned every element in CCC to offer a high quality Dark Mode experience. CCC now offers more detailed progress indication while a task is running, including a time remaining estimate. File processing and transfer rates are now... Read More


Mike's picture by Mike | May 19, 2021

CCC 5.1.27 and CCC 6 can make bootable copies of the system on Intel and Apple Silicon Macs (11.3+) right now, and we'll continue to support that functionality as long as macOS supports it.

But as Apple's platform continues to evolve, we have to design our recovery strategies around the current hardware capabilities. A bootable external device may not be a part of that strategy. CCC can do so much more than just make copies of the system, and now is the right time to revisit your backup strategy and make it even better with some of the new features in CCC 6.

For decades, Mac users have taken for granted the Mac's "External Boot" feature. Prior to Mac OS X, people could simply drag and drop the System folder from one volume to another; presto, external boot volume. When Apple made it more complicated with Mac OS X, we pioneered the "bootable backup" solution (nearly 20 years ago!), and this has been a feature we've reliably supported on every new Mac and every new OS since then.

But Apple has never been afraid of shaking things up to blaze new trails. Big Sur and the new Apple Silicon Macs have shaken up the way Mac users will recover from hardware failure.

Big Sur's Big Change

All on its own, Big Sur introduced a significant new change to the creation of an external boot device. The operating system now resides on a cryptographically sealed "Signed System Volume" that can only be copied by an Apple-proprietary utility, "Apple Software Restore" (ASR). We were already familiar with ASR, so fairly quickly we were making bootable copies of Big Sur back in November. It hasn't been perfect though. We've performed tens of thousands of ASR clones at this point, and we've discovered that ASR is just not as robust as our own file copier. There are many scenarios where ASR simply fails with no explanation. ASR is also very one-dimensional; choosing to copy the system requires that we sacrifice other backup features, e.g. we cannot copy the system and retain versioned backups of your data, we can't evaluate what was copied, we can't exclude items from the initial backup, we can't save checksum data for later verification. So, while we're certainly able to make a bootable copy of the system with ASR, it starts to feel like using it causes us to lose sight of what's actually important to back up – your irreplaceable data.

Apple Software Restore isn't quite ready for the new Apple Silicon Mac storage

When Apple introduced Apple Silicon Macs, we discovered another snag. The "Apple Fabric" storage in these Macs offers per-file encryption keys (like the storage in iOS devices), and for months, ASR didn't work with it. Apple partially resolved that in macOS 11.3, but even now using ASR to clone the system back to the internal storage of... Read More

Mike's picture by Mike | November 3, 2020

CCC 5.1.23+ can make bootable backups of Big Sur on Intel and Apple Silicon Macs.

Update May 13, 2021: CCC 5.1.27 can now make bootable backups of a Big Sur startup disk on all Macs.

Update Nov 24, 2020: 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 ... Read More

Mike's picture by Mike | May 27, 2020

Update (July 16, 2020): Apple fixed the underlying OS issue described below in macOS 10.15.6, and the CCC 5.1.20 update puts our workaround on the back burner. Every challenge opens up new opportunities, and that's actually how we're seeing this incident in retrospect. Rather than just hoping for a fix, we invested in a solution, and that solution puts us in a solid position for the next major OS.

Update (May 29, 2020): This issue is now addressed in CCC 5.1.18, which is available for immediate download – CCC can make bootable backups of macOS 10.15.5. Choose "Check for Updates" from the Carbon Copy Cloner menu to get the latest version of CCC. Special thanks to my team members for helping put this release together so quickly, the folks at Wordcrafts for a wicked-fast turnaround on these UI translations, and for several beta testers that helped us knock out some kinks along the way.

Early last week we discovered an APFS filesystem bug in a beta of macOS 10.15.5. The technical details of the bug are laid out below, but the short version is that we're no longer able to use our own file copier to establish an initial bootable backup of a macOS Catalina System volume. To be very clear – existing backups are unaffected, and this has no effect on CCC's ability to preserve your data, nor any effect on the integrity of the filesystems on your startup disk or your backup disk. The impact of this bug is limited to the initial creation of a bootable backup.

So that's a lemon... But hey, summer has arrived here in the northern hemisphere, so let's make some lemonade!

Creating bootable backups on macOS 10.15.5

Last year at Apple's Developer Conference, Apple suggested that backup software could use Apple's "Apple Software Restore" (ASR) for cloning APFS volume groups. Initially I dismissed this – I shouldn't have to use Apple's black-box utility to do my job, I prefer to take full responsibility for my backups. Anticipating a world in which Apple continues to restrict access to APFS rather than grant it, though, we decided to invest a fair amount of time evaluating this functionality, and we've been beta testing it for the last 8 months. I don't like to lean on ASR for general backups because it has some shortcomings and doesn't give any insight into its internal activity (e.g. files copied, errors encountered), but in this very narrowly-defined case, we can leverage Apple's proprietary utility just to establish bootable backups. We posted a beta last Sunday with new UI around this functionality, and we intend to... Read More

Sarah's picture by Sarah | December 24, 2019

We will be closed December 24 and remain closed December 25 to spend the holidays with our families. We will also be closed December 31 through January 1. 

Limited staff are available to respond to customer requests until January 2. We appreciate your patience if it takes a bit longer for us to respond than is typical.