I have installed 10.13 Public Beta 2 on an external Firewire drive that is currently the startup drive. It is not encrypted. It was given a clean install of 10.12.5 before starting.
There was no option to upgrade to APFS during the install process. I thought there should be an option to upgrade to APFS. So, my drive is still Mac OS Extended (Journaled).
This is the second time. Previously, I installed Public Beta 1 and there was no APFS upgrade option. So, after the install tried to upgrade to APFS by booting from the Recovery Partition and using Disk Utility. That failed with "Building boot caches on boot helper partition failed". The disk was no longer bootable and as a by-product, my Mighty Mouse was un-paired.
Does this mean APFS cannot be installed on an external (Firewire) startup drive ? Has anyone seen such a limitation ?
I've browsed the install log. I can't find any remarks about APFS install being offered, refused or failed. There was an APFS Dry Run section which noted success.
The APFS FAQs do have two ambiguous statements. First is "Apple File System is optimized for Flash/SSD storage, but can also be used with traditional hard disk drives (HDD) and external, direct-attached storage." Second is "You can use Disk Utility to convert external volumes from HFS+ to APFS format." By "external volumes" do they mean external non-startup drives ? What about external startup drives ?
Is there something obvious that I've missed ?
Thanks.
