I just attempted to restore a time machine backup after the latest Sonoma upgrade severely degraded several applications. When I selected a version I wanted to restore to on the recovery screen (created on an earlier version of Sonoma), I was informed that I would need to reinstall Sonoma first by downloading it from Apple over the internet. This was surprising to me and does not meet my expectations for how Time Machine works. If I only wanted to save selected files from the hard drive, then there are simpler, less buggy, cross platform options for doing this other than Time Machine.

Is there simple software or a simple process that is capable of doing a full restore from an external drive that does not require an internet connection?

  • 2
    I’m not sure how anything can fulfill your “ save selected files from the hard drive” with “capable of doing a full restore” since selective and full are opposing qualifiers. Are you sure those are the requirements?
    – bmike
    Apr 23 at 11:56
  • OS volumes are sealed after installation, they can‘t be restored from backup any longer.
    – nohillside
    Apr 24 at 6:03

1 Answer 1


On Sonoma (and a few earlier versions), the OS is on an entirely separate disk volume from "user data". The OS is considered 'secure', and can only be installed by trusted methods; consequently, it does not get backed up locally.

Therefore, if you want to restore an earlier version of Sonoma, your Mac has to get it from Apple. You may be able to use an installer app, but I don't think you can simply copy over the OS from another source, because the volume has to be cryptographically "signed and sealed".

Usual practice is to restore all your data -- apps, documents, settings, email, etc -- independently of the OS. But obviously, you need to have the correct OS version for things like the Mail database and other data structures.

SuperDuper! and Carbon Copy Cloner have been the go-to utilities for cloning and restoring disk volumes for many years. There are also utilities like Chronosync.

But I have to say that I've been using TM since its introduction in 2007, and I've found it entirely reliable, and a regular life-saver, both for individual files and complete restores.

  • I downloaded an installer image from Apple so I can have that on an external bootable drive separate from the time machine backup. I assume that I will be able to install from that without having to redownload from Apple? For me, the backups regularly fail and have to be restarted for unknown reasons, though today I used time machine to fix a bunch of things that I broke while trying to figure out what caused the performance degradation, so it was a "life-saver" today.
    – mushroom
    Apr 23 at 10:54
  • @mushroom Hmm. With performance issues and failing backups, I'd check that your disks are functioning correctly. It may not be the fault of the OS.
    – benwiggy
    Apr 23 at 12:15
  • See their other question where they determined it was due to a known pytorch issue.
    – Barmar
    Apr 23 at 14:48

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .