When High Sierra came out, I opted to not update my filesystem version, out of caution. Now that it’s been out for a while, and my MacBook Pro has had no issues, I’d like to upgrade my MacBook Pro 5,1 to APFS.
I naively tried by booting into recovery mode, launching Disk Utility, and selecting “Update to APFS.” Good thing I just backed up, because this made my machine no longer boot.
Searching around, it appears that High Sierra included a firmware update that let machines boot from APFS volumes, which would explain why my machine would no longer boot after updating the boot volume.
I can’t find a way to retroactively apply that firmware patch, and Google is failing me. My backup plan is to download a High Sierra installer and try installing it from scratch, and hope I get a chance to select APFS and the firmware update. But I’d like a smoother path, if anyone has one.