How to boot the ISO image when the ISO image is stored on the hard drive and not USB

[Kaplan]

My network has a limited number of USB ports. I need to boot a read-only instance of BT. I'd like to configure this to boot the ISO from the HD itself.

I'd be grateful for any grub stanza where someone got this, or anything similar, to work.

The primary OS is ubuntu, and in theory, grub supports the loopback mechanism, so I should be able to copy the ISO onto an EXT file system. A live ISO if you will, but not using a CDROM or a USB stick.

menuentry "Backtrack" {
loopback loop (hd0,2)/opt/bt4-r1.iso
linux (loop)/boot/vmlinux BOOT=casper boot=casper nopersistent textonly rw quiet
initrd (loop)/boot/initrd.gz
}

In practice, not so much.

EXT3-fs (hda2): error: couldn't mount because of unsupported optional features (240)

This was touched on in an earlier post, but the boot stanza the author was pursing required the 'find_iso/filename' capabilities, which appear not to be supported in the default version of grub. I am trying for anything that works...

[Snayler]

Have you tried google?

[orgcandman]

I might suggest also ripping the filesystem.squashfs, initrd, and kernel out of the ISO, and putting them into an appropriate place on an EXT-2 filesystem. Then you can just point grub to them and boot. This also means that if you want to do some periodic updates, you're free to customize the filesystem.squashfs any way you'd like - no restamping of a CD or re-running some UNetBootin app. Just extract the FS, modify, mksquashfs, and over-write. Next boot - you win!

[Kaplan]

Have you tried google?

Yes, thank you. If you can offer a concrete suggestion, I would be happy to try it and share the results for the benefit of everyone else.

I might suggest also ripping the filesystem.squashfs, initrd, and kernel out of the ISO, and putting them into an appropriate place on an EXT-2 filesystem. Then you can just point grub to them and boot. This also means that if you want to do some periodic updates, you're free to customize the filesystem.squashfs any way you'd like - no restamping of a CD or re-running some UNetBootin app. Just extract the FS, modify, mksquashfs, and over-write. Next boot - you win!

Interesting idea, thank you. The ISO is little more than a container, albeit a convenient one. I am still hopeful someone else has been successful with loopback, but I will poke around and see what's involved to boot from squashfs.