Bootable backups

[Shamino (David C.)]

Continuing the discussion from Back up drives:

@mschmitt

(I forsee a topic move…)

Beginning now, in anticipation of @ace moving other people’s replies…

@mschmitt

They still have value. The only thing you can’t do with them is a) boot an Apple Silicon Mac that has a SSD that is completely toast, and can’t be repaired using Apple Configurator, and b) make individual changes to system files.

Absolutely correct, but…

You can’t incrementally update the system volume. So if you want to keep that volume up to date (e.g. after a macOS upgrade), you need to redo a complete backup, which will blow away your backup history (e.g. all the incremental backups on the data volume), and will take a long time to complete.

I would suggest that if you go this route, you make it just once, and from that point forward, only make incremental backups of the data volume. The system volume may drift out of sync, but it should remain bootable, so you can use it for a quick recovery, should that become necessary, but without losing your history of incremental backups.

Maybe redo the full backup after a major upgrade (e.g. from Sonoma to Sequoia), if you are concerned that the upgrade may make changes to the data volume incompatible with the old system, but no more often than that.

Also note that Apple and people like Mike Bombich have said that this capability is not guaranteed to work, and may break in the future. So you should probably still plan for recovering the way Apple would like (use Recovery to make a clean install of macOS, then the Migration tool to restore all your content from a Data volume backup).

@mschmitt

The issue with the signed sealed volume is that it takes ASR to clone the system volume, but that’s not my problem, it is something that the developers of Carbon Copy Cloner and SuperDuper! have to deal with – which they have.

Yes and no. Yes, they have to deal with it, and yes, they have.

But the ASR utility is still mostly undocumented, so it may break in the future. And it can not perform an incremental backup - it always wipes the target APFS container. So it’s much less useful than bootable backups were before the creation of the SSV.

[mschmitt (Michael Schmitt)]

I don’t usually re-clone the system volume for minor updates. And even for a major update, what I’ve found to be faster is to apply the upgrade to the clone, rather than re-clone. That way I don’t have to re-encrypt.

I will admit that creating a bootable clone on Apple Silicon is harder than it should be, due to a bug in ASR where it results in a kernel crash. I’m hoping that is fixed in Sonoma or Sequoia.

[trilo]

My issue is the inability to instantly reboot and get back to work (from a machine/ssd failure). We kept clones whilst using OS X Server and if we had a server issue we’d simply boot from the clone (even on a new or different machine) and be back up and running in (literally) seconds. I’m not a fan of having to restore which can take quite some time. Of course the clunky way bootable clones have to be created and updated is just an added impediment.

I don’t see Apple changing things so it’s something we need to live with. It probably doesn’t affect many users but for us it was a major positive to using OS X. In my personal computing life it’s not really an issue as my data is my primary concern and can be protected with simple backups.

[gbdoc]

Not absolutely correct. I have an M2 MBAir, always up-to-date OS, and a SuperDuper clone on a fast SSD, which I re-clone every week or so or sooner with major updates. The clone obviously takes the OS with it. I can boot from it. It took a bit of fiddling to set it up (don’t remember exactly any more), but even I could do it, no technical wizard, just an experienced Mac user.