Created attachment 626448 [details] patch that helps. I think this is a more robust fix for the problem than fiddling with timeouts. If you cd /usr/lib/dracut patch -p1 < /path/to/dracut.diff mkinitrd then you should have better luck booting with a missing device. I've sent an email discussing the problem to the initramfs mailing list: http://comments.gmane.org/gmane.linux.kernel.initramfs/4075 but has not received a reply yet.