SuperDuper cloned SSD won't boot?

You select the drive you want to copy to. When you select Restore a popup appears with options to restore from.

Whether it will be notable or will work at all would be interesting to know. Good luck.

I’m going to try Restore in Recovery Disk Utility later.

I’m trying it on an Intel now. Different behavior in Recovery. Because the system and the data are split volumes on the Intel in Recovery I get a choice of which to restore the system or the data. I can’t take both, which is what you want I think Ian. Out of curiosity I’m trying to restore the system volume to see if that works. Theoretically I could then make a separate volume and use that for CCC to back up the data volume.

I am utterly shocked and surprised after all the failures creating external bootable systems I've been having. This completely worked on the Intel system. I selected the system drive to Restore, and it did the whole thing. It took the system and the associated data volume. I'm on an external drive that is a clone and behaving exactly like the system on the internal drive of the Mac.

Hi Ian. I think what your'e doing to get an external bootable drive in advance of a Fusion drive failure is smart. We recently had our 2018 27" iMac lose the spinning disk part of the Fusion duo and it took me a couple days to finally get it to boot from an external. The failed Fusion caused all sorts of problems where it could not install a fresh OS from a bootable thumb drive onto an external SSD. I ended up needing to create the bootable SSD on another Mac then use TM to migrate the User data onto it.

I got an OWC SSD kit to replace the failed spinning disk and I gotta say, out of all the years of getting into Macs to replace drives, cards, etc., this was the most nerve-wracking. On the 2018 (maybe not your 2017?) Apple used adhesive rather than magnets to hold the screen in place. Using the supplied tool to cut through the adhesive and getting the screen glass off was challenging. Once open, installing the new drive was easy but putting the screen back on with the new adhesive strips was also challenging because once the glass touches the adhesive, that's it, no real adjustments can be made so you've got to get it correct the first time.

All this to say, if any amount of downtime is unacceptable, getting your bootable drive situation figured out beforehand is smart. Wish I'd known before ours went down it was such a pain.

Thanks very much Ian.

Fortunately the Apple Fabric integrated SSDs are externally unlikely to fail. Something else might but as long as the device can be powered the enclosed system volume should work. Wonder with Apple Stores have devices that can decrypt and open the system volume in an emergency.

How do you do that?

Ah. Thank you. It doesn't work on my M1 system. It produces an error when I try. It might work on Intel. A lot more works there that no longer works on the M series machines.

Section 3 is the volume that will be erased and become the exact copy so this, in your case, is your external SSD.

Yes, it should be bootable.

I’m guessing about 20 minutes. It was about 200 GB, so not a huge amount on the internal.