I boot the .iso directly from the hard drive much (!) faster than USB with an entry like this:
Code:
sudo gedit /etc/grub.d/40_custom
#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
menuentry "saucy64 13.10" {
set isofile="/saucy-desktop-amd64.iso"
loopback loop (hd0,6)$isofile
linux (loop)/casper/vmlinuz.efi boot=casper iso-scan/filename=$isofile noprompt noeject
initrd (loop)/casper/initrd.lz
}
sudo chmod 777 /etc/grub.d/40_custom
sudo update-grub
boot and choose the entry
where the .iso is on partition 6 in my case, note the hd0,6 which would have to be altered for wherever you put the .iso.
then when the .iso is loaded, do a
sudo umount -rl /dev/sda6
install as normal.
Now note saucy is vmlinux.efi I don't know if the lubuntu vmlinuz is a .efi or not. Under file manager I open the .iso and look into the folder casper to see what the vmlinuz is.