Repartitioning an AFPS volume

I’m trying to track down why my app is so glacially slow on High Sierra. Something that takes 7 seconds on my Hackintosh/El Capitan takes 22 seconds on the MacBook Air/High Sierra.

To compare apples with apples I wanted to run both Sierra and High Sierra on the same machine. Unfortunately, VMWare still doesn’t work with High Sierra.

Then I wanted to repartition the computer. But the Disk Utility app won’t let me - the plus sign isn’t active. Is this on purpose or a bug? Is there a trick how to do this? Or should I simply reformat the computer with 2 partitions? I read that AFPS can do containers. But could I install an extra version of the MacOS on this container?

disk utility on sierra (and may be on high sierra I did not try it) lacks a lot of features compared to the previous versions.
I would boot from a 10.11 and reformat the drive or try to repartition from disk utility 10.11
(if it can do it…)

@Jean-Yves Pochez: the question is why the + sign isn’t active. Might be an AFPS thing.

I think I’ll buy a small external SSD and install Sierra and High Sierra there.

No, he’s right, they’ve been stripping away features from Disk Utility left and right. The plus sign might just be disabled because, Apple. I think that’s why there’s third party tools to handle disk partitioning, because Apple simply thinks we don’t need it.

you can do all partitionning you want using command line and diskutil
all the options are available, you may try to partition your drive that way
but the apple disk utility is for me no more working from 10.12 (and after ?)

Thanks, Jeav-Yves, I’ll try the diskutil then.

You don’t need it on iOS, so it makes perfect sense that you wouldn’t need it on the Mac .