Problems creating Yosemite USB bootable drive
Change  

sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled 2 --applicationpath /Applications/Install\ OS\ X\ Yosemite.app --nointeraction


to

sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume "/Volumes/Untitled 2" --applicationpath /Applications/Install\ OS\ X\ Yosemite.app --nointeraction


or

sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled\ 2 --applicationpath /Applications/Install\ OS\ X\ Yosemite.app --nointeraction


and it should work.

You have to escape spaces in paths in the command line either with a \ or quotation marks.