[CentOS-docs] Remastering an RPM based distribution – How To

Tue Mar 27 14:03:27 UTC 2007
Remek <service at remekmotorok.com>

 From my work with Fedora, I have a reasonably complete How To Guide 
that presently runs about 30 pages.
Although the process of remastering a distribution is not complex (once 
it is understood), explaining the how and why of each step does get a 
bit verbose.

For distributions like Fedora that have frequent updates and no decimal 
releases, having an up to date copy for subsequent installs is a very 
handy thing.
As CentOS normally issues decimal releases, this would not be such a 
great need.

However, having done so many of these remasterings with added content, 
some other benefits came to light for anyone that does a reinstall or 
needs to deploy across a number of feature rich machines.
In particular, when deploying a feature rich application such as 
workstations, when anaconda completes the install, there is usually a 
considerable amount of additional work yet to do.
Be this packages from extras, third parties, Gconf settings etc. There 
is also the task of ensuring all the proper selections were made at 
Was a check box missed and an item missing or where too many items 
selected and now using resources and space needlessly?
With a customized remastered disk, these issues can all be solved and 
the deployments made faster and more uniform.

The basics of the How To include:

Working with comps.xml:
Changing the default selections
Adding packages to groups
Adding new groups

Working with the media:
Working from a DVD iso or multiple CD iso files.
Working with physical media – DVD or CD

Collecting files:
The various repositories.
Using wget to keep your private build repository up to date.

Solving dependency hell. Using yum-utils:
Using yum-utils to report any missing dependencies makes adding packages 
much easier.
For amusement, last year I built an FC5 distribution that included all 
files from core, extras and Livna.
Yes, it was about 9 Gb when complete, but yum-utils was able to resolve 
all the dependencies even with a distribution of this size.

Adding any RPM file to the remastered distribution:
In theory, any RPM should be able to be added to the distribution and 
automatically installed.
In reality, some RPM files do not cooperate well with anaconda and I 
cover this as well.
I also cover what things are more practical to finish with a post 
install script rather than an RPM or even a custom RPM.

I have already modified my script to work with CentOS 4.92 (the iso 
directory structure was changed by RH or CentOS).
As soon as CentOS 5 final is released, I will be remastering my own copy 
to add in all of my preferred extras to make the desktop sing and dance, 
utilize my ATI and Nvidea video cards etc.
A full function workstation – out of the box.

So, if there is some interest in posting this how to on the Wiki, I 
would be willing to revise the document as needed.
To make it CentOS 5 specific or broaden the topic a bit to cover recent 
releases of RHEL, Fedora and CentOS.

Please let me know if this topic is of interest for the Wiki.

Mr. Mizzen