tl;dr

At long last, v3.5 is out, with

  • Big Sur and Monterey Bootable Backups
  • Support for macOS 10.10 and later
  • Apple silicon support
  • Various fixes and improvements (see the Revision History in the Help menu)


Under Big Sur and later, the OS is only copied if you use Erase, then copy. Everything else is updated when you use Smart Update later, of course. The What's going to happen? section will tell you what's going on.

Users on Apple silicon systems with older (pre-2019 or so) licenses will need to either purchase a new license or run under Rosetta.

Auto-update now available, or

Download SuperDuper! v3.5

Long, Strange Trip

If you're interested, the history of this version is documented in detail in earlier blog posts over the last year or so. It's taken longer than we'd hoped, but through the various Beta releases we've got a lot of testing miles under our belts, and we're pretty pleased with the way it came out.

There remain some challenges, of course. Bootable backups under macOS 11 (Big Sur) and later are a bit strange, because they don't show up immediately in the Startup Disk Preference Pane. You'll find they do show up in either Option+Boot (Intel) or Power+Boot (Apple silicon) boot menus, though. And once authorized, they boot nicely.

General Process

So, what's the process for making an initial bootable backup under Big Sur and later?

  1. First, the destination has to be formatted as APFS. To do a nice, full format, you should:
    • Open Disk Utility
    • Choose "Show All Devices" from the View menu
    • Select the destination drive hardware (above the existing volume)
    • Click Erase
    • Choose the "GUID" partition scheme (2nd pop-up), THEN "APFS" formatting (1st pop-up) and name appropriately
    • Click Erase
  2. Then, make an initial Erase, then copy backup. Erase, then copy is selected in Options under During copy.
  3. That's it!
  4. No, really, that's it.

And Then What?

To maintain your backup, use "Backup - all files" with Smart Update (again, in Options under During copy). That will update all "your stuff" (that is, everything except the operating system), and things should still boot normally even if the OS is updated.

When you want to update the version of macOS on the backup, you can make an Erase, then copy backup again, as above.

Does My Backup Have to be Bootable?

It does not. If you start with a fresh drive or APFS volume, as above, a "Backup - all files" with Smart Update will only copy "your stuff" (that is, the macOS "Data" volume).

This can still be restored via migration after a clean OS install, of course...nothing is missing save for the OS, and you can download that any time.

What About Encryption?

A bootable backup cannot start out encrypted, due to macOS rules about creating volume groups. So, after you create a bootable backup, start up from it, turn on FileVault (you don't have to wait for it to finish), then boot back to your regular drive.

Ensure the password is added to the keychain when prompted, and that's all there is to it. Subsequent Smart Updates will maintain the encryption.

Regulations Require My Data To Always Be Encrypted

No problem. While you can't have a bootable backup without the brief gap between backing up and encrypting, a non-bootable backup, as above, can start with a volume formatted encrypted. Just use "Backup - all files" with Smart Update.

Anything Else I Need to Know?

If you get a "Resource Busy" error during an Erase, then copy error under Big Sur and later, it's likely your Mac fell asleep during the copy, even though we asked it to stay awake. You can usually fix this by installing Coca from the App Store (it's free!) and using it to keep the Mac awake during this process.

You may notice that, if an Erase, then copy backup fails under Big Sur and later, the backup drive has been renamed to the name of the source drive.

This is because those backups are done with asr, a system tool that does a low-level replication of the drive. Along with the data comes the drive name. After a successful copy, we rename the drive to its original name, but if asr fails, the drive never gets renamed. Fully erasing, as above, will fix it.

Nap Time

So, that's about it, save for whatever I've neglected to mention! Thanks for your patience as we worked through this release - your support and encouragement is sincerely appreciated. Not much left, except to

Download SuperDuper v3.5