by Mike | October 19, 2017

Well, I did it. I know that I've told many people I'd be waiting until Thanksgiving to apply the High Sierra upgrade to my own production machine, but after some reflection this week, I decided that High Sierra was ready for me, and that I was ready for High Sierra. I've always been decidedly anti-upgrade when it comes to my own production system. Upgrades tend to break things, and I just can't afford downtime on my laptop. High Sierra and the APFS transition, to me, was a potential double-whammy for breaking things, so I was bearish on this upgrade in particular. But today, we're ready.

I didn't make this decision lightly. The scientist in me kicked into gear and I started analyzing some data. I looked at new OS adoption among our user base, I looked at our Help Desk analytics, and I considered the experiences of the users that I've been helping over the past several weeks. As I predicted early in the summer, the APFS conversions have largely gone just fine. This is probably at least partially attributable to Apple backing off on applying the new format to Fusion and AppleRAID devices, but I think some credit to Apple is due here. They pulled this off! The upgrade hasn't been flawless, but based on the feedback that we've received from our users, largely it has gone fine, and anecdotally I think it has gone better than past OS upgrades.

OS adoption among CCC 4 and CCC 5 users

Looking at just the last week, I can see that approximately a quarter of CCC users have upgraded to High Sierra. Sierra remains the dominant OS choice, but I think we'll see that flip in the next three to four weeks; perhaps once the 10.13.1 release is posted.

OS Adoption among CCC 4 and CCC 5 users, second week of October

CCC rises to the APFS challenge

So how did CCC do with the upgrade? In the 16-year history of Mac OS X, High Sierra was the first OS upgrade to introduce a new, bootable filesystem format, so obviously that posed a challenge to the bootable backup solution. In just four months, we picked apart the boot semantics of this new filesystem, added format-agnostic support to CCC 5, tested dozens of source/destination filesystem combinations, assembled numerous pages of support documentation and several new Help videos – CCC was ready for APFS when High Sierra shipped on September 25.

I don't want to be the guy that hoists a "Mission Accomplished" banner too early, but looking back at the last several weeks, we were more prepared for this OS release than any major new OS in the past. We've seen great success making HFS and APFS bootable backups on High Sierra. Our statistics show thousands of confirmed High Sierra bootable backups using both APFS and HFS (roughly 40/60 split), and based on user feedback on our... Read More

by Mike | September 29, 2017

One of our users made a startling discovery this week after upgrading to High Sierra. He had an HFS+ formatted 16TB RAID device, and had always intended to enable encryption on that volume. There's no OS on it, so he simply right-clicked on the volume in the Finder and chose the option to encrypt it:

Screenshot of Finder contextual menu showing encryption option

This is an easy way to enable encryption on a volume: plug in a password, verify, add a hint, done!

Prompt for encryption password

Oddly, though, CCC, Disk Utility, and Terminal all agreed that his HFS+ volume was now an APFS Encrypted volume. Naturally he contacted AppleCare. "Not possible, says Apple", he reported.

It is apparently possible, however, and I was able to confirm this behavior on my test system. Take any HFS+ formatted volume that does not have an installation of macOS on it (that part is key), right-click on the volume in the Finder and choose the option to encrypt it. Rather than simply converting the volume to a CoreStorage Encrypted volume and keeping the HFS+ format, macOS converts the volume to APFS with no warning, and then enables encryption.

Potential hazards of converting your data volumes to APFS

Apple has demonstrated that the conversion from HFS+ to APFS has gone pretty smoothly, but there are a few scenarios where you might want to give some serious thought to that kind of conversion.

Did I want my expensive RAID device to be my APFS Guinea Pig?

APFS is supported atop RAID devices, so this conversion will surely work out just fine. That's what I'd be telling myself had this happened to me, but I'd certainly have appreciated some warning. Deciding to turn on encryption has one set of implications, and we've had our hands on HFS+ CoreStorage encryption since OS X Lion, so there aren't many surprises left. Adding a filesystem format change might make me decide that this is a bit too risky for this particular device. What if there's a specific issue with my vendor's RAID? Wouldn't I at least like the opportunity to reach out to that vendor for comment before casually flipping this irreversible switch?

APFS Encrypted volumes are not backwards-compatible

Do you share your disk between Macs? APFS Encrypted volumes aren't backwards compatible at all, so if you attach that converted disk to a Mac running an older version of the OS, you're greeted with this heart-attack-inducing error message:

The disk you inserted was not readable by this computer

I'm using the term "older Mac" fairly loosely, this... Read More

by Mike | September 26, 2017

The time for betas is over! High Sierra is here. APFS is here. We're ready for both, and we've got you covered. APFS, HFS, encrypted, not encrypted, FileVault – whatever your source or destination, we support all of these combinations in CCC 5. We've tested so many different scenarios, we put the results into a chart to keep track of them.

"Can I continue to back up to an HFS+ volume, or do I have to erase the backup disk as APFS?"

Over the last day or so, we've been getting this question a lot from folks that have upgraded to High Sierra. This new filesystem has generated so much confusion, we even got the question, "Can I still back up to an HD platter-based disk?" We expected some concern about what's supported on each end, but the lack of support and readiness for all of these combinations from other products is causing even more confusion than we anticipated.

My answer is that all of these configurations work with CCC 5, and that you don't have to change how your destination is formatted. CCC 5 automatically archives the special boot volumes associated with an APFS source, and automatically populates them, as necessary, if you have an APFS destination (even if the source is HFS!). We specifically tested all of these scenarios and set up a "command central" for our testing and for reporting issues that we're seeing that are specific to macOS High Sierra:

High Sierra Testing and Known Issues

I hope that chart goes a long way toward relieving concerns about what is an acceptable source and destination format for your High Sierra backups. But just to reiterate:

  • CCC can clone your High Sierra SSD to an SSD or an HDD that is formatted as either HFS or APFS.
  • CCC can restore an HFS-formatted High Sierra backup to an APFS or HFS volume.
  • CCC can make bootable APFS backups.
  • CCC can make bootable HFS backups.
  • You can mix and match APFS and HFS sources and destinations – CCC will make the destination bootable.

CCC handles the special APFS "helper" volumes seamlessly, and quietly

Only CCC has supported Recovery HD archiving and cloning since Apple introduced that special volume in OS X Lion five years ago. The semantics for creating and populating those volumes are a bit different for APFS, but these special APFS helper volumes are very similar to the HFS Recovery HD volume. As a result, our intellectual and technical investment that we made in recovery volume support over the last five years has paid off. We were able to add support for APFS helper volume archiving and creation fairly quickly, and we spent the bulk of the... Read More

by Mike | September 14, 2017

On Tuesday Apple announced the release date for macOS High Sierra – we can expect to see it on the App Store on September 25. We've been busy testing High Sierra over the summer, and I'm happy to say that we're ready for it. We've posted an update to CCC 4 that fixes a couple cosmetic High-Sierra-specific issues, and we're preparing to release an update to CCC 5 with the same fixes, plus more improvements that are specific to High Sierra. As soon as Apple posts a "Golden Master" build of High Sierra, we will proceed with our last push to update documentation, screenshots, videos, etc. We'll have more documentation and videos coming in the next couple weeks about CCC and APFS, so stay tuned!

Preparing your Mac for the High Sierra upgrade

Before you upgrade to High Sierra, it is imperative to understand that downgrading to your previous OS will be impossible without a bootable backup of the previous OS. Before you apply the upgrade, we recommend that you establish a bootable backup of your current OS on an external USB, Firewire, or Thunderbolt hard drive, then verify that you can boot your Mac from that backup disk. Before you pull the trigger on the upgrade, detach that external disk from your Mac and set it aside.

For more detailed advice on preparing for the upgrade and instructions on how to downgrade, check out this CCC knowledgebase article:

Best practices for updating your Mac's OS.

Preparing yourself for the High Sierra upgrade

Perhaps the biggest change in macOS High Sierra is the new filesystem that Apple will be applying to your Mac's SSD/Flash-based storage upon upgrade. This change will be mostly transparent for many users, but if you have several disks, complex partitioning, or if you're just curious how these things work, you might want to take a moment to learn more about this new APFS filesystem. Apple offers a couple helpful APFS-related knowledgebase articles here:

Apple Kbase HT208018: Prepare for APFS in macOS High Sierra
Apple Kbase HT208020: Upgrade macOS on a Mac at your institution

In regard to how CCC will work with your APFS-formatted volumes, this CCC knowledgebase article aims to answer all of the questions you might have on the subject:

Everything you need to know about Carbon Copy Cloner and APFS

If you have additional questions, please let us know! You can reach us right from within CCC — choose "Ask a question" from CCC's Help menu to receive personalized... Read More


by Mike | August 18, 2017

I introduced CCC to the world over 15 years ago. With the debut of CCC 5 within reach, I thought it would be neat to see how CCC has changed over the years. I still remember the day that I published a description on VersionTracker and anticipated the response. Would people like it? Would someone else beat me to the solution? I've been thrilled with the response I've gotten from users over the years, and I'm happy to say that I've grown this little seed into a successful company that produces and supports a great product.

Conception: November, 2001

Before CCC, I wrote an AppleScript that performed the very basic tasks of copying files from one volume to another while retaining Unix permissions and ownership. The Mac OS X bootable backup was born! This little script never saw the light of day, though. Instead, I made the extra push to turn it into an application that would be accessible to more people.

CCC 1.0: January 18, 2002

This was the quintessential "1.0" release. All of the basic features were there for a simple clone from the startup disk to a backup disk.

CCC 2.0: November 2002

2.0 allowed you to choose any volume as the source. Look at those fancy buttons! And a scheduler! Documentation!

CCC 3.0: September 2007

The long gap between 2.0 and 3.0 was not a break. I spent those years diving deeper into the startup procedure of Mac OS X and I learned a lot. I wrote other applications too, including one that was used to clone hundreds of Macs all at the same time. I was also having kids :-). I remember bouncing my son in his baby bouncer while writing code at 3AM for CCC 3.0. It's amazing that I can look at sections of code and remember those moments so clearly, like a smell can remind you of a childhood memory.

CCC 3.4: July 2011

There were several dozen releases of CCC between 3.0 and 3.4, but this was the first big one after I left Apple.

CCC 4.0: October 2014

Not long after Lion was introduced I completely stripped CCC down and rebuilt it. The result was spectacular – a refreshing new task-centric interface and scheduling that felt built-in, not added as an afterthought.

... Read More