Technic Dynamic is a source of education focused in the following categories of technology: (Computer - Design - Gadgets - Networking - Security) Link : http://technicdynamic.com
Main » 2012»February»7 » Chapter 4 : Obtaining System Installation Media | 6. Automatic Installation
11:57 PM
Chapter 4 : Obtaining System Installation Media | 6. Automatic Installation
Automatic Installation
For installing on multiple computers it's possible to do fully
automatic installations using the Ubuntu Installer itself.
Automatic Installation Using the Ubuntu Installer
The Ubuntu Installer supports automating installs via preconfiguration
files. A preconfiguration file can be loaded from the network or from
removable media, and used to fill in answers to questions asked during the
installation process.
The Ubuntu installer has preliminary support for automating installs using
Kickstart files, as designed by Red Hat for use in their Anaconda installer.
This method is not as flexible as the preconfiguration file method above,
but it requires less knowledge of how the installer works.
This section documents only the basics, and differences between Anaconda and
the Ubuntu installer. Refer to the
Red Hat documentation for detailed instructions.
To generate a Kickstart file, install the
system-config-kickstart package and run
system-config-kickstart. This offers you a graphical
user interface to the various options available.
Once you have a Kickstart file, you can edit it if necessary, and place it
on a web, FTP, or NFS server, or copy it onto the installer's boot media.
Wherever you place the file, you need to pass a parameter to the installer
at boot time to tell it to use the file.
To make the installer use a Kickstart file downloaded from a web or FTP
server, add ks=http://url/to/ks.cfg or ks=ftp://url/to/ks.cfg respectively
to the kernel boot parameters. This requires the installer to be able to set
up the network via DHCP on the first connected interface without asking any
questions; you may also need to add ksdevice=eth1 or similar if the
installer fails to determine the correct interface automatically.
Similarly, to make the installer use a Kickstart file on an NFS server, add
ks=nfs:server:/path/to/ks.cfg to the kernel boot parameters. The method
supported by Anaconda of adding a plain "ks" boot parameter to work out the
location of the Kickstart file from a DHCP response is not yet supported by
the Ubuntu installer.
To place a Kickstart file on a CD, you would need to remaster the ISO image
to include your Kickstart file, and add ks=cdrom:/path/to/ks.cfg to the
kernel boot parameters. See the manual page for mkisofs for details.
Alternatively, put the Kickstart file on a floppy, and add
ks=floppy:/path/to/ks.cfg to the kernel boot parameters.
Additions
The Ubuntu installer supports a few extensions to Kickstart that were needed
to support automatic installations of Ubuntu:
The rootpw command now takes the
--disabled option to disable the root password. If
this is used, the initial user will be given root privileges via
sudo.
A new user command has been added to control the
creation of the initial user:
user joe --fullname "Joe User" --password iamjoe
The --disabled option prevents any non-root users
from being created. The --fullname option specifies
the user's full name, as opposed to the Unix username. The
--password option supplies the user's password, by
default in the clear (in which case make sure your Kickstart file is kept
confidential!); the --iscrypted option may be used to
state that the password is already MD5-hashed.
A new preseed command has been added to provide a
convenient way to preseed additional items in the debconf database that are
not directly accessible using the ordinary Kickstart syntax:
The --owner option sets the name of the package that
owns the question; if omitted, it defaults to d-i, which is generally
appropriate for items affecting the first stage of the installer. The three
mandatory arguments are the question name, question type, and answer, in
that order, just as would be supplied as input to the
debconf-set-selections command.
As of Ubuntu 6.10, the keyboard option takes X layout
names. To use an X keyboard variant, set this option to
layout_variant, with appropriate values of
layout and variant. For
example, in_guj selects the Gujarati variant of the
Indian layout.
You may use the apt-install command to install packages
in %post --nochroot scripts (although you might also
choose to generate a %packages section in a
%pre script and include it using
%include). Note that this does not work if the
post-installation script is run in the chroot environment.
Missing features
As yet, the Ubuntu installer only supports a subset of Kickstart's features.
The following is a brief summary of features that are known to be missing:
LDAP, Kerberos 5, Hesiod, and Samba authentication.
The auth --enablecache command to enable
nscd.
The bootloader --linear,
--nolinear, and --lba32
options for detailed LILO configuration.
Upgrades. To upgrade from one Ubuntu release to another, use the facilities
provided by apt and its frontends.
Partitioning of multiple drives. Due to current limitations in the partition
manager, it is only possible to partition a single drive.
Using the device command to install extra kernel
modules.
Driver disks.
Firewall configuration.
Installation from an archive on a local hard disk or from an NFS archive.
The lilocheck command to check for an existing LILO
installation.
The logvol --percent,
--bytes-per-inode, and
--fsoptions options for certain kinds of detailed
Logical Volume Management (LVM) configuration. (LVM configuration in general
is experimentally supported as of Ubuntu 9.04; please let us know about your
experiences with it.)
Restrictions of a partition to a particular disk or device, and
specifications of the starting or ending cylinder for a partition.
Checking a partition for bad sectors.
RAID configuration.
The xconfig --monitor option to use a specified
monitor name.
Most package groups. As special cases, the "Ubuntu Desktop" and "Kubuntu
Desktop" groups install the standard Ubuntu or Kubuntu desktop systems
respectively, and any group name not containing a space (for example,
"ubuntu-desktop") causes packages with the corresponding Task: header in the
Packages file to be installed.
Exclusions in %packages sections are no longer supported as of Ubuntu 6.10,
as a casualty of other improvements. You may need to use a %post script
instead to remove unnecessary packages.
Pre-installation scripts and non-chrooted post-installation scripts may only
be shell scripts; other interpreters are not available at this point in the
installation.
