The live cd file system is currently one big lump which takes a while to generate as well as being inflexible. It should rather be an ordered list of squashfs-es that are mounted on top of each other.
The current method of building the live fs makes customising the live cd harder than it needs to. It also means building another live fs for the DVD images (with additional language packs or similar) will take a long time.
- John wants to create a customised live CD. He takes the base livefs and builds a custom squashfs with the packages he wants, then drops that into /casper on and burns it to a CD.
- Ubuntu wants to have a DVD image with more language packs than what there's room for on a CD. The livefs build process therefore creates a separate squashfs with just the language packs on and makes it available to the DVD build process.
Data preservation and migration