I have a 2013 iMac running Mavericks. I would like to make a virtual machine of OS X using VirtualBox, and I can't find any way to do it and I have no idea why. I have tried every version of OS X that I have (Snow Leopard Sever on Disc, and Mountain Lion and Mavericks as downloads from the App Store). I have turned the install discs into ISO and CDR files, tried them as dmgs, and for some reason everything results in a "no bootable media" error. I have no idea why this is happening. Using this same setup I have made virtual machines for Windows and Linux distros with no problems, but OS X never seems to work. Does anyone have any experience of using VirtualBox on a Mac? What is so different about installing OS X?