About Carbon Copy Cloner

[Ben Jenssen]

Two things I learned about CCC lately:

1: Changing media, you lose snapshots.
I recently bought a bigger drive for my backups. I figured I'd just copy or clone the old one and continue backups where I'd left off. Then I noticed that the CCC clone of disk(s) was smaller than I expected. Size like a fresh clone, without snapshots. Copy with Disk Utilities or CCC, same result.
I contacted Bombich, and they said, yes, snapshots are a part of APFS file system and can't be copied.

So, be aware; changing backup disk media, you lose snapshots and roll-back ability.

2: Without thinking, I moved a 50gb folder to another directory on the same disk. My daily CCC backup of course copied that and my backup disk lost 50gb of free space.
Contacted Bombich, they said only way to retrieve that space was to wait for CCC settings to "thin" out the original folder automatically, or for the disk to reach full space limit, and then thin.
So, I've set the CCC task now to not keep anything older than 10 days, and the 50gb will be released in 10 days.

CCC is a great backup software, and Bombich provide good service, I just thought I'd let you know.


(By the way, I told them CCC should have the option to delete files/folders across snapshots, even Timemachine can do that.)

[cwsand]

Thanks - good to know!!

[Righty27]

Thanks for sharing, Ben.

I feel that the most useful thing here for Mac users reading this is to appreciate that the way that APFS works with snapshots, copies, links, etc. is not always what they might expect having used previous file systems.

https://eclecticlight.co/2019/01/05/...-mojaves-apfs/

I imagine that your situation was complicated by an expectation that your CCC backup would also copy/carry over the built-in ‘backup’ capability provided via snapshots, so not really an issue with CCC itself.

In my experience, Mike Bombich and his team provide some of the best support in the business and they have helped me endlessly to refresh/develop my backup strategy following my migration to APFS, well beyond questions related to their product, allowing me to learn, buy the right drives, etc. ... very different to another Mac backup app developer I also use!

[Ben Jenssen]

I agree w/everything you wrote, Righty.

And of course, I had great, almost immediate help from Bombich to help me understand this.