title Install ubuntu-gnome-14.04 root (hd0,6) kernel (hd0,6)/vmlinuz boot=casper iso-scan/filename=/ubuntu-14.04.3-desktop-amd64.iso ro quiet splash locale=zh_CN.UTF-8 initrd (hd0,6)/initrd.lz
hd(0,6)是第一块硬盘上的第3个逻辑分区C,D(hd(0,4)),E(hd(0,5)),F(这个盘hd(0,6))
卸载isodevice
sudo umount -l /isodevice