No, I was not able to find a way to boot directly from an iso image. But it was also not the intended goal. Since grub works independently of the kernel and disk image, I can copy the compressed-cloop file (usually KNOPPIX or such), along with the kernel and minirt file, save it to my flash drive, and it would work great. Some distributions, like DamnSmallLinux rarely ever change kernels (DSL 2.3 still uses 2.4.26), I don't even need to copy over those files.

Although not much, copying the entire iso would take up a little more space. Not only are there extra files on the iso image, but there's the properties of the iso image files (Joliet and RockRidge extension information) that would all need to be saved on my flash drive. This is probably not much, but I'm working with a 256 MB drive.

So the short answer is no. But let me know if you come across a way to do it!

documented on: Tue, 2006-04-25, Jeremy Turner

The short answer is yes :). I just spent the past two days to find out how.

use grub for dos (http://grub.blogeden.com/ - it's in chinese though)

If you just want to do something like in linux live cd, i.e., the iso file is used to host the systems files, it's easy and straightforward to use iso.

If you want to boot from a iso file on a harddisk, do something in menu.lst like

title Boot from iso on a harddisk
map (hdX,Y)/your.iso (hdZ)
map --rehook
chainloader (hdZ)+1
rootnoverify (hdZ)
boot

The iso file must be in one chunk - contig from sysinternal http://www.sysinternals.com/Utilities/Contig.html may come handy. It's a good idea to use fat32 to host the iso file.

Also check out http://www.911cd.net/forums/index.php?showtopic=15617&st=20&p=101928&#entry101928 and http://www.911cd.net/forums/index.php?showtopic=18045

documented on: 2006-10-04, Anonymous

http://www.microsoft.com/technet/sysinternals/utilities/contig.mspx

Contig is a single-file defragmenter that attempts to make files contiguous on disk. Its perfect for quickly optimizing files that are continuously becoming fragmented, or that you want to ensure are in as few fragments as possible.

documented on: 2007-10-22