chrfr wrote:
"Mojave requires APFS and it will convert your disk automatically."
I don't think this can be "categorically stated" as of yet.
It's not definitely known whether or not Mojave will run under HFS+.
Has Apple issued a statement to this effect?
There may be a method to install it to an HFS+ volume that (so far) is undocumented or perhaps there's a terminal command to do it that is not widely known yet.
I'm thinking that one could:
1. Install Mojave as APFS
2. Use CarbonCopyCloner to clone the install to an HFS+ formatted volume.
3. Boot and run Mojave that way.
Until someone tries this and gives us a report.... it's
"as of yet unknown".
EDIT:
I tried opening CCC 5.1.2 in Mojave.
It opened, but gave the warning that it wasn't certified for use with the [new] OS yet. After the warning, it wouldn't do anything.
So... I'll guess that we'll have to wait for a version of CCC that IS certified for use with Mojave before the above can be tried...
EDIT2:
Please see this thread:
https://forums.macrumors.com/threads/benefits-of-apfs-on-fusion-drive.2122751/#post-26143524
Looks like it can be done.
CCC cannot do it at this time.
But it looks like SuperDuper
-can-.