Has anyone tried to run Yosemite Beta in a VM? I'm running Snow Leopard on my Mac Pro and wanted to check out Yosemite but I don't really want to dual boot - whenever I reboot the system the dumb Apple RAID card often loses its marbles and thinks the 3rd/spare disk in my RAID5 setup is missing, which is super annoying. So I try not to reboot it unless it's absolutely necessary. Anyway I tried to install Mountain Lion into a new VM in the latest VirtualBox 4.3.14 release, thinking I could install ML and then upgrade to Mavericks and then install the Yosemite Beta. I'm not getting very far with that. I get a white screen near the end of the Mountain Lion installer phase and then it eventually black screens on me with a few lines of output and then it just sits there. I've already got an external 4 GB Time Machine disk so that's taking up my available USB port and power plug. Is an external bootable drive really the only viable option in this scenario?