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Re: Distro Howto??

[I am no more on the LI-* lists, so listadmin, please forward]
Sandip Bhattacharya wrote:
> Is there any place I can get to know how a distro instalaltion works?
> I have been a RedHat user all this while. What has always made me
> curious is how a RH distrib installs itself ...
I had written about this to LIH sometime ago...
> 1. How does RPM install itself on a new system? Or upgrade itself to a
> new version like in RHL7?
The rpm program used for installation is found on the CD itself,
and not the one on the HDD. This one incidentally installs an
rpm-*.rpm along with the others.
> 2. How does it manage to upgrade glibc on a disk when it has itself
> booted from a CD ...
rpm --root=/whatever ...
> 3. How in the order of installation, visible above the progress-bar
> during installation, it manages to install dependencies of the
> package(like glibc) after the package itself.
rpm v3.0 and above (the software, not the packaging format) internally
rearranges the list of software to install inside what is known as
a transaction set. If the transaction set + installed software
satisfies all the dependencies, then the software is installed in
the original order (not in the corrected order within the transaction
As a matter of fact, all the above is done within a library called rpmlib.
There are interfaces to rpmlib from various programming languages (C, perl,
python...) so you can also use these features in your program.
Further questions, ask...;-)