I have an instance of Mac OS Sierra on an external drive that I'd like to run as a VM for easy access, as well as retain the ability to boot from for better performance. The reason is the usual: out of date software that I still have some use for, but not quite enough to pay upgrade and subscription fees for. I already do this with a Bootcamp partition but it's unclear if/how I could do it with a Mac external drive. I know I can run a standard Mac guest VM from an external drive - I just want to use the whole drive as the VM. Thanks. Parallels 15 running Mac OS Mojave
