DLoop comments

[Matt Zimmerman]

On Thu, Sep 29, 2005 at 11:13:00AM -0400, Phillip Susi wrote:
> Matt Zimmerman wrote:
> >
> 
> Yes, there is more to installing a .deb than extracting the files, but 
> one part of installing the .deb is extracting the files, so when you do 
> so, if you remove the files from the .deb and leave everything else, 
> then you can reinstall it later by getting the files from their already 
> installed locations, and processing everything else needed to install 
> the package normally, which is still contained in the package.

It sounds simple until you consider things like conffiles, diversions,
Replaces, and other features of the packaging system beyond unpacking files.
I honestly believe that the complexity of this solution outweighs its value
in comparison to the alternatives, but you're welcome to attempt it.  You
might consider looking at dpkg-repack as an example of prior art in this
area.

> What I meant by this line of discussion is that you may not build a 
> livedc filesystem with pristine installations of the packages, you may 
> need to configure them a bit after they are installed.  Such 
> configuration may be different on the livecd than on the hard drive.

It was a design goal of the Ubuntu live CD that there be no such
configuration required when building the filesystem.  Any necessary
configuration is done at boot time, so the filesystem can be replaced with
any Ubuntu installation.

> It is really just a potential problem that I thought might come up with 
> copying the files when I decided that the reason the livecd doesn't 
> simply have an option to copy all the files to the hard drive already 
> must be because it isn't that simple.
> 
> You have convinced me though, that copying is probably the best thing to 
> do.  Of course, if any configuration problems DO crop up that would make 
> installing from the debs desirable again, then I think my idea is still 
> a good one.
> 
> Also one of the reasons I thought of this was because the DLoop Wiki 
> seems to go to great lengths trying to come up with ways to save space 
> on the livecd yet still be able to install from the .debs.  I assumed 
> there was a good reason to want to install from the .debs.

Installing from .debs is definitely more flexible (network installations,
custom package selections, server installations and the like), and it's
worthwhile to discuss this class of solutions because it would be valuable
to be able to support all of the use cases without compromise.  However, the
copy approach is an example of optimizing for the common case (in this case
a desktop install), where we have a faster and simpler, but less flexible,
option available.

-- 
 - mdz