Is it possible to setup read-only root ?

[David G. Miller]

John Wendel <jwendel10 <at> comcast.net> writes:

> 
> On 07/01/2012 12:17 PM, jdow wrote:
> > [SNIP]
> 
> > The equivalent is done with live CDs you know.
> >
> > {^_^}
> 
> I think you just supplied the answer! I didn't think of it, but the 
> equivalent of a live CD is exactly what I need. Now I just need to 
> figure out how to build a live CD like system, minus the compressed 
> filesystem stuff and I should be there.
> 
> I should have mentioned earlier that this box is going to be a dedicated 
> media player, with the compact flash drive as it's only disc. I know I 
> should probably just use openelec or geexbox, but that would take all 
> the fun out of it. I will try to steal the init system from one of these 
> dedicated distributions, but I really want to build the system with 
> Fedora packages as much as possible.
> 
> Thanks everyone for sharing your knowledge.
> 
> John
> 

The live CD systems that I've dealt with have all created a minimal, in-RAM /
(or root) using ramfs.  Just boot with your favorite live CD distro, open a
terminal and run mount.  It does mean that the image of / can be read-only and
it takes surprisingly little RAM to have the bits of Linux in RAM that are
actually volatile.

Cheers,
Dave