Boot ISO images from GRUB2

English Install/Boot/Login
1

I have installed Opensuse Leap 42.1 on a 32GB usb stick. The usb is partitioned sda1 fat32 (/data) and sda2 ext4 ( / ).
I did a “normal” installation from Opensuse DVD using the pendrive as if a “normal” hard disk, then I changed / and /data options in fstab including the option noatime
The pendrive is a usb3.0 but it is a very good pendrive (sandisk extreme) and it works like a charm even when used on usb2.0.
When I boot a computer with it, it present grub menu and boot opensuse.

Then I want to add sobre ISOs to the boot menu (for instance I have system rescue cd iso on /data/ISOS). I have found this and this (last one is in spanish) but they talk about booting ISO images from a “fixed” OS. the problem is that they specify something like this


menuentry "**openSUSE 12.3 DVD**" {   set isofile=**/openSUSE-12.3-DVD-x86_64.iso**
  set root=(**hd0,1**)
  loopback loop $isofile
  linux (loop)/boot/**x86_64**/loader/linux install=hd:$isofile
  initrd (loop)/boot/**x86_64**/loader/initrd
}

and the problem with that is this hd0,1 because I don’t know if I will boot a computer with one hard disks, two, none of them… so I don’t know if my usb stick will be hd0, hd1, etc.

Is there any to avoid this “set root” or to force the pendrive to be always hd0 whn booting with it?

regards

2

I’m pretty sure that how the disk is identified is controlled by your BIOS, and there’s nothing you can do about that.

I’m not certain, but I think you can replace that “set root=(hd0,1)” with:


search --no-floppy --fs-uuid --set=root  some-weird-string

except that you replace “some-weird-string” with the UUID of that partition. Then it won’t matter whether the disk is “hd0” or “hd3” or whatever.