In the last couple of days, Apple has revealed that the High Sierra installer will not convert its very popular Fusion Drives to the new APFS file system — yet.
First, there seems very little point in any Mac with a Fusion Drive (or hard disk) being upgraded to High Sierra. APFS is High Sierra’s big new feature, and without it the upgrade seems nugatory.
Second, anyone using a mix of Macs running Sierra and High Sierra will be wisest not to use APFS on removable drives, as the systems still running Sierra will be unable to access anything on them. For many organisations, that will make High Sierra inadvisable until all Macs can be upgraded to it.
Hmm. This is a bit confusing; and it seems quite stupid on Apple’s part. Apple’s technical note, mentioned in the article, makes this all very unclear. If you have more than one Mac, and have external drives, you need to really think carefully.
This is about as clear as knowing which USB-C cable you need for certain devices.
Apple doesn’t seem to be doing well with making these new technologies user friendly.