Re: Distro howto??

[Arun Sharma <arun@xxxxxxxxxxxxxxx>]

On Mon, Apr 02, 2001 at 03:06:15PM +0530, Sandip Bhattacharya wrote:
> [Not exactly a programming question. Sorry.]
> 
> 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 suspect that some of this qualifies as "intellectual property" for
the distro vendors :)

> 1. How does RPM install itself on a new system? Or upgrade itself to a
> new version like in RHL7?

Since redhat has a everything is a RPM view, things are simple: install
a whole bunch of RPMs. Upgrade ? upgrade the rpms.

> 2. How does it manage to upgrade glibc on a disk when it has itself
> booted from a CD ...

Actually, that's a lot simpler than upgrading glibc that the installation
program itself is linked to. In the early days of redhat, I got burnt
several times trying to upgrade glibc only to find that ls and other essential
programs stopped working.

I think the key is: /sbin has a bunch of statically linked binaries, that 
help you recover the system.

> 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.
> 

I guess it uses rpm -q? commands to figure the dependencies and then do
a rpm -i on those guys. As someone said, look at their python code.

	-Arun