August 22, 2017 Update: We have published a Kbase article that offers more up to date information on this subject here: Everything you need to know about Carbon Copy Cloner and APFS

Apple introduced macOS "High Sierra" this week, and along with many other developers, we've eagerly started dissecting the new operating system to see what's new. Like in past years, those living on the bleeding edge are wondering, "Will CCC work with this new OS?". Or perhaps "when" prepended to that same question. The short answer is that we have already posted a version of CCC that offers preliminary support for High Sierra. If you're running the Developer Preview of the new OS, open CCC and choose "Check for updates" from the Carbon Copy Cloner menu to get the update. We've found a few issues of concern in the new OS. We addressed some of these issues in the current version of CCC; some will be dealt with in future beta updates as we continue testing.

Will I have to pay for an update to CCC that works with macOS High Sierra?

When we have completed CCC 4 qualification on High Sierra, we will issue an update to CCC 4 that is free to all current CCC 4 license holders.

Will CCC work with Apple's new filesystem, APFS?

The current version of CCC 4 already works with APFS insofar as CCC can copy files to and from that filesystem. The current version can also make bootable backups from an APFS startup disk to an HFS+ formatted destination volume – we've already tested that, and in the little bit of testing that we've done so far, that works great. The current feature set of CCC 4 will be qualified against High Sierra – creating bootable HFS+-based backups and working with CoreStorage encrypted backups will be qualified and functional (barring any OS bugs) and we aim to complete that by the time Apple ships High Sierra in the Fall.

Creating a bootable APFS volume, however, is brand-new territory. The semantics of starting a Mac from an APFS volume are completely different from those of an HFS+ volume. We have established a procedure to create an APFS startup volume, though, and we've even created a proof-of-concept bootable APFS clone. What lies ahead is a massive amount of engineering work to build support for these new procedures into CCC. APFS encryption is also handled quite differently from CoreStorage encryption, so we have a lot of work to do in regard to building in support for automatically unlocking and mounting APFS encrypted backup volumes. We're aiming to offer new functionality for creating APFS bootable (and optionally encrypted) backups by the time Apple ships macOS High Sierra in the Fall.

Stay tuned to our blog for updates on our progress and other news from Bombich Software. This will be an exciting Summer!