CD Customization

The process of customizing or "remastering" ubuntu cd's is not espcially complex, but it is a little tedious and finicky. My knowledge of the process is also imprefect so hopefully other people will modify this page as appropriate.

The install cd has two main parts: an IsoLinux-derived OperatingSystem, which is the environment in which DebianInstaller runs; and a DebianRepository structure, which is what takes up all that space on the disk in the directories "pool" and "dists". Building a new CD involves modifications to both parts.

Modify installer behaviour using a Preseed file

When the CD boots up, a linux kernel is started and the installation tasks are initiated. The installer's default behaviour can be modified through the use of a "preseed" file, which feeds DebianInstaller ("d-i") answers to questions normally asked by debconf or in other contexts. If you look closely at your install cd, you'll see that certain options (e.g. "server", "expert", "oem") already have preseed files assigned to them.

So, suppose you are installing breezy on a bunch of identical computers and you already know the answers to certain questions (what country and time zone you're in, what keyboard you have, how the network should be configured, how you wnat to partition the hard disk, etc. etc.). You can "preseed" the answers to these questions in a very simple configuration file.

Changing isolinux.cfg to idnetify your preseed

If you wnat

This is relatively straightforward and fairly well-documented, though DebianInstaller (d-i) is under such heavy development that, for instance, breezy is already importantly out-of-sync with sid, so not all of the documentation you find on the web applies to breezy's installer.

2. Modify pool structure to include/delete packages

Example

xxx

Display

xxx