Update: According to SuperDuper developer Dave Nanian, Apple has resolved this issue in macOS 15.3.
The backup issues present in macOS 15.2 Sequoia are impacting Apple’s Time Machine utility, along with third-party applications such as SuperDuper and CarbonCopyCloner. While the problem initially seemed confined to bootable backups, it appears to be either more widespread or involves multiple bugs that are affecting Mac backups.
The Origins of the Issue with SuperDuper
Initially, the developer of SuperDuper at Shirt Pocket utilized its own code to create bootable backups of Mac volumes, until Apple restricted developers to use its own replicator functionality.
Following the failure of SuperDuper’s bootable backups, the company identified that the issue originated from a bug in Apple’s replicator code within macOS 15.2.
macOS 15.2 launched recently, bringing with it an unexpected and unfortunate surprise: Apple had broken the replicator.
Towards the completion of replicating the Data volume, specifically when it attempts to copy either Preboot or Recovery, it fails with a Resource Busy error. In the past, users could overcome Resource Busy by keeping the system active; however, this new bug renders that ineffective on most systems, resulting in a persistent failure.
With Apple removing the capability for third-party developers (like us) to replicate the OS and assuming that task itself, it is now Apple’s responsibility to ensure that this feature works effectively. They have unfortunately fallen short with macOS 15.2. Since this is their proprietary code, OS copying will not function until they rectify the issue.
Moreover, Synology reported that the same issue is affecting bootable backups to their NAS devices.
Broader macOS 15 Sequoia Backup Issue(s)
CarbonCopyCloner has also been impacted, which typically supports bootable backups; however, users have reported that even (non-bootable) Time Machine backups are failing as well.
macOS 15.2 disrupts Time Machine backups. A friend lost their entire backup history due to Time Machine malfunction.
The issue seems primarily related to Apple Silicon Macs.
We have contacted Apple for a comment and will provide updates as we receive a response.
Source: Daring Fireball. Image by Samsung Memory on Unsplash.
: We use income-earning auto affiliate links. More.
