Open VirtualBox software and click the New button to create a new VM for MacOS.
In the Create Virtual Machine window, type the name of the macOS system in Name section. Select …
Configure a minimum of 4 GB RAM for the macOS High Sierra VM and click on the Next button.
To create a new virtual hard disk for the macOS High Sierra VM, select Create a new virtual hard …
Select VDI (VBox Disk Image) for macOS High Sierra VM hard disk file type and click Next button.
You can configure the macOS VM disk in 2 types. Dynamically allocated: Quickly create a virtual …
Storing the hard disk of the macOS VM in a different location is useful for performance. To change …
Select your Portable Hard Disk and create a new folder for the VM and click the Open button on the …
Click the Save button to save the virtual hard disk of the Mac OS High Sierra.
You can configure the virtual hard disk size to 30 GB. Click the Create button to create a VM hard disk.