One or more backup errors in macOS 15.2 Sequoia affect Apple's own Time Machine utility, as well as third-party apps SuperDuper and CarbonCopyCloner.
The issue initially seemed to only affect bootable backups, but it now appears that it is either more general or that multiple bugs are affecting Mac backups…
It all started with SuperDuper
SuperDuper developer Shirt Pocket originally used his own code to create bootable backups of Mac volumes before Apple locked everything down, forcing developers to use the company's own Replicator functionality.
After SuperDuper's bootable backups began to fail, the company investigated and discovered that the bug was in Apple's Replicator code in macOS 15.2.
macOS 15.2 was released a few days ago with a surprise. A terrible, terrible surprise. Apple broke the replicator.
Towards the end of replicating the Data volume, apparently when it goes to copy Preboot or Recovery, it fails with a Resource Busy error. Previously, Resource Busy could be worked around by ensuring the system remained awake. But this new bug means there is no fix for most systems. It just fails.
Since Apple took away the ability for third parties (like us) to copy the OS and took responsibility for it, they had to make sure that functionality continued to work. And in this they failed in macOS 15.2. Since it's their code and we have to rely on it to copy the OS, copying the OS won't work until they fix this.
Synology has said the same issue affects bootable backups on its NAS systems.
Wider macOS 15 Sequoia backup bugs
CarbonCopyCloner was also affected, which again usually supports bootable backups, but then users reported that (non-bootable) Time Machine backups also didn't work.
MacOS 15.2 breaks Time Machine backups. My friend had his entire backup history wiped by Time Machine.
Best comment by Shivam Pandey
I too was struggling with this macOS 15.2 backup issue. My Time Machine backups failed to create and I felt lost trying to figure out how to recover my data. I used Stellar Data Recovery for Mac which helped me recover everything I thought was lost. Although the underlying issue with Apple's replicator code is still not resolved, I am thankful that I did not lose any important files. Hopefully Apple will fix this issue soon.
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This issue appears to be specific to Apple Silicon-based Macs.
We've reached out to Apple for comment and will update if we hear back.
Via Daring Fireball. Photo by Samsung Memory on Unsplash.
