KVM: Install CentOS / RHEL Using Kickstart File (Automated Installation)

Kickstart is a network installation system for RHEL, Fedora and CentOS Linux distributions. Another good option is Cobbler which is a Linux provisioning server that centralizes and simplifies control of services including DHCP, TFTP, and DNS for the purpose of performing network-based operating systems installs. In this tutorial, I’m going to show you how to use kickstart file to install CentOS.

Create Kickstart file

An automated installation method to install CentOS / Fedora or RHEL is recommend to automate procedure. Using kickstart, a system administrator can create a single file containing the answers to all the questions that would normally be asked during a typical RHEL Linux installation. Use kickstart GUI tool called “Kickstart Configurator” (run system-config-kickstart command to start the tool) to create a file called ks.cfg as follows:

auth  --useshadow  --enablemd5
bootloader --location=mbr
zerombr
clearpart --all --initlabel
text
firewall --enabled --port=22:tcp
firstboot --disable
keyboard us
network --device eth0 --bootproto static --ip 10.10.21.76 --netmask 255.255.255.240 --gateway 10.10.21.100 --nameserver 10.10.21.1,10.10.21.2 --noipv6
network --device eth1 --bootproto static --ip 123.1.2.6 --netmask 255.255.255.240 --gateway 123.1.2.100 --nameserver 10.10.21.1,10.10.21.2 --hostname centos.nixcraft.in --noipv6  
lang en_US
logging --level=info
url --url=http://mirrors.nixcraft.in/centos/5.5/os/x86_64/ 
reboot
rootpw --iscrypted $1$somepassword
selinux --enforcing
skipx
timezone  America/New_York
install
part / --bytes-per-inode=4096 --fstype="ext3" --grow --size=1
part swap --recommended
%packages
@core
--nobase
%post
( 
echo '10.0.0.0/8 via 10.10.21.100' > /etc/sysconfig/network-scripts/route-eth0
sed -i 's/LABEL=\//& console=ttyS0/' /etc/grub.conf
echo 'S0:12345:respawn:/sbin/agetty ttyS0 115200' >> /etc/inittab
echo "ttyS0" >> /etc/securetty
echo 'IPV6INIT=no' >> /etc/sysconfig/network
echo 'install ipv6 /bin/true' >> /etc/modprobe.conf
) 1>/root/post_install.log 2>&1

Upload this file to a web server as ks.cfg. You can use nfs server too.

virt-install: Install CentOS using Kickstart

Type the following command:
# virt-install \
-n centos \
-r 2048 \
--vcpus=1 \
--os-variant=rhel5.4 \
--accelerate \
-v \
-w bridge:br0 \
-w bridge:br1 \
--disk path=/emc/kvm/centos.img,size=100 \
-l http://mirrors.nixcraft.in/centos/5.5/os/x86_64/ \
-nographics \
-x "ks=http://10.10.21.3/static/ks.cfg ksdevice=eth0 ip=10.10.21.76 netmask=255.255.255.240 dns=10.10.21.1 gateway=10.10.21.100"
The -x option is used to pass additional kernel command line to the installer when performing a guest install. The ks option sets ks file location and rest are networking options so that installer can fetch ks.cfg and do automated installation for you.