[mdlug] Booting CD images from a hard drive partition

[Michael S. Mikowski]

On Monday 23 March 2009 08:20:50 Aaron Kulkis wrote:
> Drew wrote:
> > I wish to set aside one or more partitions on the new hard drive for
> > holding a copy of
> > a Linux boot CD, such as Knoppix, PC-OS, or RIPLinux, to have a copy
> > ready to boot without needing to dig out the CD.
> > ...
> > BTW: I am aware that there is an "install to hard drive" option when
> > the CD itself is booted. I'd
> > rather not use that if I can avoid it; I rather like the 'it's a
> > fresh system every reboot' aspect of booting
> > from the CD. I just want to do it without actually using the CDROM drive.
>
> Why not just copy the CONTENTS of the iso filesystem onto
> a native filesystem (say, ext3) on a partition, and boot that?
>
> You sound like someone who is says they want to get to the
> top floor of a skyscraper and want to know what path to take
> up the outside wall of a skyscraper, completely ignoring the
> fact that there are staircases and elevators already in
> place for precisely that purpose.
>
> The solution is NOT to cram a square peg into a round hole.
> use mkfs to create a filesystem on the partition, mount
> the .iso file, and then boot that partition.
>
> This is very simple.  The only thing difficult is your
> insistence upon a really, REALLY sub-optimal choice of
> configuration elements (i.e. using a .iso file as the
> system to boot off of).  ISO's have a lot of limitations,
> beyond the particular one you're facing at this point.

It sounds to me like this should work.  In fact, this could be one way the 
developers test their live CD builds (the other, which I have used a few 
times, is to mount an iso image through a loopback device and use VMWare).

I think the key point is Drew wants the system to boot as if it is coming from 
the CD, e.g. use of a ramdisk instead of mounting file system, and all the 
other magic that occurs when the distro determines it is mounting off a 'live 
CD'.

The only problem I could see is if the copied iso contents start acting 
differently because on boot they recognize they are coming from a hard drive.  
But that seems unlikely.

Cheers, Mike