You will need at least 4096 MB RAM of host memory, more is better. MacOS Sierra 10.12.6, VirtualBox 5.1.28 with installed VirtualBox Extension Pack
It's always a struggle to get macOS as a guest system running on macOS as the host system, but today was my lucky day and after several failures I managed to get it running! So here is how I did it. So I have a MacBook Pro running macOS Sierra (10.12) and I wanted to run a virtual machine (VM) of macOS High Sierra to try out the new operating system. 8Okt/17 0 VirtualBox: How to create a macOS High Sierra VM to run on a Mac host system