How to determine file paths in software RAID when booting from GRUB?

Question

RAID

Such a question - I uploaded the Ubuntu image to disk, and I want to boot from it: I
use a similar option:
menuentry "Kubuntu Live" {
set root=(hd0,3)
loopback loop /iso/kubuntu-12.04.3-desktop-i386. iso
linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=/iso/kubuntu-12.04.3-desktop-i386.iso noeject noprompt -- initrd
(loop)/casper/initrd.lz
}
the fact that I have a software RAID and the path to the iso-shnik is not determined in any way.
What should I do?