Skip to Content

macOS Sequoia 15.3 Fixes SuperDuper Bootable Backups Bug

by

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

iphone fold text

iPhone Fold Crease Measurements Revealed as Device Hits Production

Wednesday February 25, 2026 5:37 am PST by
Apple has submitted production line orders for its upcoming foldable iPhone, effectively confirming that the device will launch this year, claims a Chinese leaker. According to the Weibo account "Fixed Focus Digital," assembly lines recently received the orders from Apple, which has apparently allowed the leaker to learn the crease measurements for the device's 7.8-inch inner display....
Read Full Article • 136 comments
Low Cost A18 Pro MacBook Feature Pink

Leaker Says Apple's Lower-Cost MacBook Will Have These 8 Limitations

Wednesday February 25, 2026 9:25 am PST by
Apple is expected to unveil its long-rumored lower-cost MacBook next week. Given it will be more affordable, this MacBook model will obviously have some reduced specs and compromises compared to the MacBook Air and MacBook Pro. While we are still waiting for Apple to announce the new MacBook, a leaker has shared eight alleged limitations to expect, based on an internal version of Apple's...
Read Full Article • 358 comments
m3 macbook pro blue

M5 Pro and M5 Max MacBook Pro: What to Expect

Wednesday February 25, 2026 3:02 pm PST by
Apple is working on a new MacBook Pro that could launch next week ahead of the "Special Experience" planned for March 4, so we thought we'd highlight all of the rumors about the device so far. Design There are no rumors of design changes, and we are expecting the upcoming M5 MacBook Pro models to look just like the M4 versions. Apple will continue to offer 14-inch and 16-inch size options,...
Read Full Article • 78 comments

Top Rated Comments

D
Daalseth
14 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)
H
H2SO4
14 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
Infinite Vortex
14 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)
M
Moka Akashiya
14 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
Blackstick
14 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)
L
Lounge vibes 05
14 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)
Read All Comments