MacOS Sequoia 15.2 appears to prevent third-party utilities from creating bootable backups. Dave Nanian, the developer behind SuperDuper (a software for creating bootable backups of Macs), reports that a potential bug in macOS Sequoia 15.2 disrupted the application’s ability to perform these backups.
A “novelty” that goes badly
The developer describes the problem very clearly on his blog :
Apple broke the replicator. Towards the end of data volume replication, apparently when it is about to copy pre-boot or recovery, it fails with a Resource Busy error.
In the past, Resource Busy could be bypassed by ensuring the system remained awake. But this new bug means that on most systems there is no fix. It simply fails.
While Apple had previously made it more difficult to boot Macs from external drives due to privacy and security concerns, now with macOS Sequoia 15.2, the ability for third-party software to copy the operating system for Bootable backups seems impossible.
Nanian is obviously disappointed by this “novelty”:
Because it’s their code and we’re forced to rely on it to copy the OS, the copy of the OS won’t work until they fix it.
To put it bluntly, it sucks. It’s bad enough that we have to work around other bugs in this code, but when it completely breaks, we’re forced to point fingers and come up with workarounds that don’t involve the replicator.
This issue specifically affects the creation of bootable backups, obviously leaving data backups like Time Machine unaffected. Other backup apps, like Carbon Copy Cloner, have moved away from offering fully bootable backups due to changes made by Apple engineers, particularly with Apple Silicon’s Signed System Volume, which can prevent a Mac to boot if it is modified, even with a bootable external disk.
You will have understood, only Apple can solve this problem, even if no update is expected before 2025. Some hope that this is a bug, and not an intentional decision by Apple. Apple aims to limit the creation of third-party startup disks.
About SuperDuper
According to its designer, SuperDuper is the most advanced and easy-to-use disk copying program available for macOS. It can, of course, perform a full backup, or “clone” — in just a few moments, you can completely duplicate your startup drive to another drive, partition, or image file. In even less time, you can update an existing clone with the latest data: use Smart Update and, a few minutes later, your backup is completely up to date!
A free trial version is available on the official website.
