macOS Sequoia 15.3 Fixes SuperDuper Bootable Backups Bug

Apple's latest macOS Sequoia 15.3 update appears to have resolved a bug that prevented popular backup utility SuperDuper from creating bootable backups, according to developer Dave Nanian.

superduper macos
The fix addresses an issue introduced in macOS 15.2 that caused SuperDuper to fail during the final stages of creating bootable backups due to a "Resource Busy" error when attempting to copy system preboot or recovery files.

Apple requires third-party apps to use Apple's own replication tools rather than directly copying the operating system. When these tools malfunctioned in macOS 15.2, it directly impacted SuperDuper's ability to create bootable backups.

"macOS 15.3 is now out, and with it, a fix for the broken replicator," Nanian wrote on his Shirt Pocket Watch blog. "As such, macOS copying will work again with 'Erase, then copy' backups."

However, Nanian cautions that while the specific replicator bug has been fixed, this doesn't guarantee that booting from backup copies will work in all situations. This is largely due to changes that Apple has made in macOS and recent Mac hardware in the name of enhanced security.

For example, Apple Silicon Macs require that the internal SSD remains functional for external booting to work, meaning a Mac with a failed internal drive won't boot from a SuperDuper backup, even if the backup itself is perfectly intact.

Popular Stories

m5 macbook pro deal

Why You Shouldn't Buy the Next MacBook Pro

Tuesday February 10, 2026 4:27 pm PST by
Apple is planning to launch new MacBook Pro models as soon as early March, but if you can, this is one generation you should skip because there's something much better in the works. We're waiting on 14-inch and 16-inch MacBook Pro models with M5 Pro and M5 Max chips, with few changes other than the processor upgrade. There won't be any tweaks to the design or the display, but later this...
iOS 26

Apple Releases iOS 26.3 and iPadOS 26.3

Wednesday February 11, 2026 10:07 am PST by
Apple today released iOS 26.3 and iPadOS 26.3, the latest updates to the iOS 26 and iPadOS 26 operating systems that came out in September. The new software comes almost two months after Apple released iOS 26.2 and iPadOS 26.2. The new software can be downloaded on eligible iPhones and iPads over-the-air by going to Settings > General > Software Update. According to Apple's release notes, ...
Apple Logo Zoomed

Apple Expected to Launch These 10+ Products Over the Coming Months

Tuesday February 10, 2026 6:33 am PST by
It has been a slow start to 2026 for Apple product launches, with only a new AirTag and a special Apple Watch band released so far. We are still waiting for MacBook Pro models with M5 Pro and M5 Max chips, the iPhone 17e, a lower-cost MacBook with an iPhone chip, long-rumored updates to the Apple TV and HomePod mini, and much more. Apple is expected to release/update the following products...
iPhone 16e Bottom Crop

Apple Reportedly Unveiling a New iPhone Next Week

Tuesday February 10, 2026 1:51 pm PST by
Apple plans to announce the iPhone 17e on Thursday, February 19, according to Macwelt, the German equivalent of Macworld. The report said the iPhone 17e will be announced in a press release on the Apple Newsroom website, so do not expect an event for this device specifically. The iPhone 17e will be a spec-bumped successor to the iPhone 16e. Rumors claim the device will have four key...
Apple Logo Black

Apple Acquires New Database App

Wednesday February 11, 2026 6:44 am PST by
Apple acquired Canadian graph database company Kuzu last year, it has emerged. The acquisition, spotted by AppleInsider, was completed in October 2025 for an undisclosed sum. The company's website was subsequently taken down and its Github repository was archived, as is commonplace for Apple acquisitions. Kuzu was "an embedded graph database built for query speed, scalability, and easy of ...

Top Rated Comments

13 months ago
“Apple Silicon Macs require that the internal SSD remains functional for external booting to work, meaning a Mac with a failed internal drive won't boot ('https://eclecticlight.co/2021/01/14/m1-macs-radically-change-boot-and-recovery/') from a SuperDuper backup, even if the backup itself is perfectly intact.”

[HEADING=3]WTF? Then what’s the point of a bootable backup? So the internal drive fails I need to get a new MB, or more likely a whole new Mac? That is ridiculous. [/HEADING]
Score: 16 Votes (Like | Disagree)
13 months ago

Apple locking down macOS is the direct result of users not caring about security and privacy yet expecting to be made whole when their bank accounts and credit cards are compromised. It helps but you can’t fix stupid.
Please provide evidence for that ridiculous assertion.
Score: 11 Votes (Like | Disagree)
Infinite Vortex Avatar
13 months ago
I love SuperDuper! as an app but I stopped using it quite a number of years ago given Apple making it difficult.
Score: 7 Votes (Like | Disagree)
13 months ago
Yeah, prohibit booting from external SSD when internal one is dead is definitely about security, and nothing about buying new motherboard/mac from Apple. You know, there is so much data on your external SSD about internal one when you boot from another one, you can access everything just like that!
Score: 7 Votes (Like | Disagree)
Blackstick Avatar
13 months ago
This was a wildly useful app in the fun old days where one could boot Macs from external volumes by holding the option key alone with a firewire drive. There's a lot less need for it today, between Time Machine and Backblaze for offsite cloud, it has been sufficient.

Time moves along. Lots of ignorant users coming in... is why Apple continues to lockdown macOS. Early 2000s was a more fun time for OSX because effectively, nobody used it. Different era today.
Score: 5 Votes (Like | Disagree)
13 months ago

If it happens to me, instant lawsuit. I use 2 backups anyway, carbon copy cloner and superduper. TM is junk and always has been junk
I think your lawsuit would get thrown out pretty quick lol
Score: 4 Votes (Like | Disagree)