Install OS X 10.10 Yosemite in VirtualBox
Due to the high usage of this guide and the lack of comfort in Gist's commenting area, I decided to make a blog post out of this which you can find here:
http://blog.frd.mn/install-os-x-10-10-yosemite-in-virtualbox/
I think instead of using mount and unmount, one should use attach and detach for hdiutil.