10.14.1 update conundrum

[2stepbay]

Before leaving for a trip, I cloned my iMac's fusion drive to an external SSD. I'm now using that drive on a friend's similar iMac. No problems accessing the drive, reading/writing etc.

Yesterday Apple released 10.14.1, however, Software Update shows no update available. So I attempted to install the latest version from the App Store. No problems downloading the 6GB installer, however upon installation, the installer would not allow me to designate the SSD drive since it was not formatted for APFS. I realize this is not a SuperDuper problem per se, however curious if anyone has encountered something similar and devised a workaround. I realize Apple's quest to simplify the User experience is at play here. However, not giving me an option to install APFS or not prevents me from upgrading the drive.

As an aside, when I return home next week I'll reclone/update my iMac's drive from the SSD. I don't anticipate running into any problems via the latest SD version. But checking here nonetheless. Thanks

[dnanian]

Sorry - haven't using their installer on an SSD without APFS...

[2stepbay]

I just learned Fusion Drives are now updated to APFS upon Mojave install. Don't remember seeing any Apple notice about APFS compatibility. Is the convert to APFS automatic, or would that be something I would have to select? If the former, seems my SSD drive ought to be APFS as it was cloned from the iMac after the Mojave install. However, Disk Utility indicates the SSD external drive is not APFS. Appreciate any insight. Thanks

[dnanian]

It's all automatic as far as I know. But it wouldn't convert an external to APFS, since you didn't actually run the installer on that drive.

[2stepbay]

Thanks Dave. So to be clear: cloning the Fusion drive to the external would only carry across the APFS if the external drive is formatted for APFS. Is that correct?

[dnanian]

"Carry across the APFS" isn't really the way to think about it. Because we're copying files - not the "disk format".

I would format the external as APFS if the source is APFS.