Splitting the installer into 2 (or more) CDs?

Colin Watson cjwatson at ubuntu.com
Mon Nov 12 17:17:12 GMT 2007

On Mon, Nov 05, 2007 at 01:41:37PM +0000, Rory McCann wrote:
> I'm making a custom edubuntu based distribution mostly to add some extra
> packages and include some custom files. I'm following the guide here:
> https://help.ubuntu.com/community/InstallCDCustomization. However my
> distro is now 712MB and won't fit on one CD.
> How can I split this into 2 CDs? Ideally I'd like to have all stock
> edubuntu stuff on CD #1 and all my stuff on CD #2. I'm using preseeding
> to customise the install, so I'd like to have it install edubuntu and
> then prompt for CD #2 and install software from that. i.e. all the
> software should be installed by the installer.

I'm sorry to say that the installer doesn't have this facility at the
moment. We had to take it out way back in Warty in order to simplify
things, since we didn't want the "are you going to use another CD?"

The closest thing we have right now is the add-on CD system we use for
Edubuntu, but that isn't handled by the installer.

This is also the case for Debian right now, BTW; it was a casualty of
the rewrite of base-config into several udebs that run before the first
reboot (which is a great improvement in most other respects). The
relevant Debian bug is:


I think the most straightforward way to fix this would be to add a
boolean question to apt-setup, asked in the cdrom generator, which, if
set to true, causes it to (carefully!) unmount /cdrom and /target/cdrom,
run apt-cdrom to prompt for further CDs, and then put all the mount
points back at the end. We could then just preseed this question to
false in Ubuntu. As far as I know, pkgsel and tasksel should support
media-change requests from apt, although this hasn't been tested very
much due to apt-setup not supporting it.

I'm not sure I'll have time to fix this myself, but I'd be happy to
review a patch and/or explain further if you'd like to look into this.

> I'm basing this off edubuntu dapper,

6.06 will be more difficult still; media-change support wasn't present
in debconf-apt-progress until 7.04, unfortunately.

As an alternative approach, there might be some low-hanging fruit you
can remove from the CD ...

Good luck,

Colin Watson                                       [cjwatson at ubuntu.com]

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