dpkg/dselect/methods/multicd

Installation methods for multiple binary CDs
--------------------------------------------

This package provides three new methods to be used within dselect in
order to access Debian binary packages stored across multiple binary CD
ROMs. It will install itself into the methods directory from dselect
so the user will be able to use them immediately.

These are the three new methods:

. Multiple binary CD-ROMs

. Multiple binary CD-ROMs, accessed through NFS

. Multiple binary CD-ROMs, pre-mounted

Acquiring package data
---------------------

Since this method is derived from the `mounted' method the user is
able to access up to five binary directories within `dists/stable':

. main
. contrib
. non-free
. non-US
. local

The selected method will try to read the `Packages.cd' file from each
of these directories if it is available.

Identifying the CD-ROM
----------------------

A unique name is associated to each CD. This name should correspond
with the label on the front of the CD. The name is also available on
the CD, so the system can find out which CD is in the drive at any
time.

Installing the files
--------------------

At the beginning of the installation the `multicd' package will sort
the list of to-be-installed packages and install them CD by CD. If a
different CD-ROM is required the user will be prompted to exchange
the CD-ROM.

Preparing multiple binary CD-ROMs
---------------------------------

Since the `multicd' methods need to know which packages are on which
CD-ROMs one cannot use regular `Packages' files. An additional data
field "X-Medium:" is required. The first CD-ROM from the set should
contain all `Packages.cd' files. To be more convenient you should
include the `Packages.cd' files on all CD-ROMs. This ensures that
you don't have to start with the first CD-ROM all the time.

Additionally the package needs to gain information which CD-ROM is
currently used. Thus each CD-ROM contains the file `.disk/info'
which contains the symbolic name for the CD-ROM as specified by
"X-Medium:".

In order to be able to create the modified `Packages.cd' files, this
package installs a modified version of `dpkg-scanpackages' in
/usr/bin. You'll need to specify the used medium with `-m medium'.

To split the `main' distribution into two CD-ROMs you'll need to
create a `Packages.cd' file for each `binary-$arch' directory.
Afterwards you simply append the second one to the first one and
put the resulting `Packages.cd' file into both `binary-$arch'
directories.

dpkg-scanpackages
-----------------

This package provides an improved version of `dpkg-scanpackages'
which comes with the following additional features:

. It can read compressed overrides files

. Using `-m ' you can tell the program to add the new data
field "X-Medium:" for each record in the output.

This version is installed using `dpkg-divert' which will disable the
original `dpkg-scanpackages' program.

Sample Layout
-------------

CD1 .disk/info = "Debian GNU/Linux binary-i386"
dists/stable/main/binary-all/
binary-i386/Packages.cd.gz
binary-i386/net/foo.deb
contrib/binary-i386/Packages.cd.gz
non-free/binary-i386/Packages.cd.gz
non-US/binary-i386/Packages.cd.gz

CD2 .disk/info = "Debian GNU/Linux contrib-i386"
dists/stable/main/binary-i386/Packages.cd.gz
contrib/binary-all/
binary-i386/Packages.cd.gz
binary-i386/net/foo.deb
non-free/binary-i386/Packages.cd.gz
non-US/binary-i386/Packages.cd.gz

CD3 .disk/info = "Debian GNU/Linux non-free-i386"
dists/stable/main/binary-i386/Packages.cd.gz
contrib/binary-i386/Packages.cd.gz
non-free/binary-all/
binary-i386/Packages.cd.gz
binary-i386/net/foo.deb
non-US/binary-all/

To re-generate the Packages file you have to chdir into
`dists/stable/$part' and issue `dpkg-scanpackages' as follows. It's
assumed that you regular compressed overrides files in
/pub/debian/indices.

CD1: dpkg-scanpackages -m "Debian GNU/Linux binary-i386" \
binary-i386 /pub/debian/indices/override.hamm.gz \
dists/stable/ > binary-i386/Packages

CD2: dpkg-scanpackages -m "Debian GNU/Linux contrib-i386" \
binary-i386 /pub/debian/indices/override.hamm.contrib.gz \
dists/stable/ > binary-i386/Packages

CD3: dpkg-scanpackages -m "Debian GNU/Linux non-free-i386" \
binary-i386 /pub/debian/indices/override.hamm.non-free.gz \
dists/stable/ > binary-i386/Packages

Please direct comments to Martin Schulze