ccc, yosemite

Will CCC work with [insert Apple's pre-release OS here]?

Will CCC work with [insert Apple's pre-release OS here]?

Every time Apple makes a new operating system available to developers, we spend several weeks evaluating CCC on that new OS. We look for changes to the features and behavior of the HFS+ filesystem, how the new OS supports (or fails to support) network filesystems, changes to the boot process, changes to support for USB, Firewire, and Thunderbolt -- and a bunch of other things. If nothing has changed and no problems are encountered, the process takes a couple weeks. Realistically, it takes at least three weeks to complete qualification, and in the worst case scenario (e.g. Snow Leopard and Lion), it takes several months to fix problems or add support for new OS and filesystem features. It's a lot of work -- a lot more than the average developer would face when a new OS is released because our software relies so heavily on filesystem functionality and operating system behavior (especially stuff that is poorly documented or not documented at all, like the Recovery HD). We clone the OS, and when Apple ships a new OS, we'd better be doing that correctly.

Because the qualification process consumes so much of our time, we approach it in two phases:

  • Evaluate functionality on the Developer Preview. Identify major problems and develop a strategy and timeline to resolve them. As problems are addressed, we may post betas for external evaluation.
  • When the GM is announced and delivered to developers, we complete final qualification. Our final product is ready when the "Golden Master" is made available to customers on the AppStore.

It would be foolish for us to complete a thorough qualification on the Developer Preview because a) the Developer Preview is usually quite buggy and Apple's bugs waste my time and b) qualification on the Developer Preview has no relevance to the final product -- we would have to repeat qualification as soon as the Golden Master is posted. Based on experience with past OS X releases, cloning software should not be used to clone new OSes until it has actually been tested on the new OS. While that seems like a common-sense statement, it's apparently not a common practice. That's our policy, though, and that's why you get a dialog that says CCC isn't qualified on Yosemite.

Last year, I had time set aside to produce a beta that would work on Mavericks shortly after the Developer Preview was made available. The announcement of Mavericks was highly anticipated, so I could budget my time really well. This year, Yosemite came with less warning. As a result, I'm in the middle of other work that can't be set aside to start Yosemite evaluation. I plan to start evaluating Yosemite in a few weeks, though, and I hope to provide a beta once any surprises are sorted out.

For every major release of OS X since 10.3, we have had a qualified version of CCC ready the moment that Apple shipped the new OS, and we will have a qualified version of CCC for Yosemite as well. In the interim, we strongly recommend that you heed Apple's advice to not run Yosemite on a production system. If you need to clone or restore a Yosemite volume, you can do that with CCC while booted from your production Mavericks volume (with the understanding that it has not yet been tested, of course).


If you're interested in participating in our beta testing program, please subscribe to our Carbon Copy Cloner-Yosemite Beta Testing mailing list. As of the Developer Preview 5, we're still waiting on a bug fix from Apple before opening up beta testing. We anticipate that happening in early September.


Mike Bombich
Bombich Software, Inc.