Why I do not see anymore, 'recovery disk' pressing 'alt' key during startup? All the latest years in several mbp and with several osx versions, I had this option. Now, I cannot see it anymore? Why? Where it is? Also I would like to make an emergency usb flash disk, to be able to boot, in case of internal hard disk failure. Please believe me, before asking here, I tried many things I found on internet. A program called Diskmakerx, does not work. Terminal commands, using an already downloaded installer of yosemite in /applications folder, did not worked too. I also tried to find and download a full copy image of Yosemite, about 6gb filesize. I tried to restore it to a usb flash disk using Disk utility, but although it transfer it, it does not shown up for selection when I press 'alt' key during startup. Please, help me find the most straight and easy way, to make such a bootable flash disk. Please give me some help from something you have tried yourself, not just a link of an article, that it is supposed to work, but it does not. (tried so many things).