backup disk formatting

[dnanian]

No, Dan, it won't. If the system does not know how to communicate with APFS, the drive won't even mount.

[Dan Lester]

That makes sense but, as I recall, when I plugged that APFS SSD in to my High Sierra 2011 Mac, an icon DID appear on the screen. That's why I assumed I could back up to it. And when I commanded SuperDuper to back up to it, it ground and ground for twenty minutes and pretended to be backing up. It was only when I tried to boot from that backup twenty minutes later that the SSD didn't show in the Boot Manager. That is, the Boot manager knew that it wasn't a compliant disk, but SuperDuper didn't seem to be aware that it wasn't.

[dnanian]

Dan, it made the copy as it should. It didn't "pretend" to back up. (Feel free to send me the log to verify.)

If the boot manager doesn't see it, it may have had the wrong partitioning scheme, or High Sierra had never been *installed* to the system (it had been restored, or copied from elsewhere) and thus the BIOS doesn't have APFS capability, even if the *system* does.

[Dan Lester]

OK, that makes sense. Now, because I couldn't do the backup with APFS, I was assuming that High Sierra couldn't manage APFS. It can! I reformatted the backup disk to APFS with the High Sierra machine I'm backing up, did another SuperDuper backup to it and ... Boot Manager couldn't see that backup again. Same problem.

So to the extent a backup is really being made, for some reason the Boot Manager can't see it. The backup disk icon is sitting the desktop, as normal, and, if I can click on it, it has inside what sure looks like a backup. So the issue is precisely with the Boot Manager.

As I said, if I format the disk as MacOS Extended, and do the backup, the Boot Manager can see the disk just fine.

I am sending you the SuperDuper log for that backup.

[dnanian]

Install the OS on this system, Dan. (Sorry, didn't connect the log - which I got before this - to this forum thread.)

[Dan Lester]

OK, let me wrap things up here. Dave and I did some discussion offline, but he finally suggested just dumping my High Sierra and reloading it. That took some effort as the Apple instructions for recovery were poor, and loads of people have had problems with the "The recovery server could not be contacted" error and the 2000F error in the reinstall package which were a big waste of time. But I finally just went to the App Store, downloaded the OS and over-installed it that way. Bottom line is that now everything works GREAT. I can now back up to an APFS drive, and boot from it, which for some bizarre reason I was unable to do before. Problem solved. So my OS just got corrupted in some subtle way. Thanks to Dave for his sage advice.

[dnanian]

The OS wasn't corrupt - the BIOS/EFI wasn't updated... and that only happens when the OS is installed.