Monday, 12 January 2015

Complete Guide for PXE Server configuration in RHEL 7.0

The Preboot Execution Environment (PXE) is an industry standard client/server interface that allows networked computers that are not yet loaded with an operating system to be configured and booted remotely by an administrator.
Let us work on RHEL 7.0 to configure a PXE Server to boot and install RHEL 7.0 OS in the client configuration. 
First setup Static IP Address for PXE server, this is important. you can edit the network configuration file or use nmcli command to setup.For setting up the static IP address click here to know more.

ip add show
Check the details with nmcli command more information about the Network settings.
# nmcli con show eno16777736
nmcli more info
Install vsftpd and createrepo packages into the server using YUM. this is to configure the software repo.
# yum install vsftpd createrepo
yum installation of vsftpd createrepo
Mount the RHEL 7.0 DVD in the server to copy the packages required to configure software repo.
# mount -t iso9660 /dev/sr0 /mnt

create a directory /rhel7/dvd/ under  /var/ftp/pub to hold the dvd packages. and copy the DVD contents to this directory.
# mkdir -p /var/ftp/pub/rhel7/dvd/
# cp -rv /mnt/* /var/ftp/pub/rhel7/dvd/
copy packages from dvd to pxe
create yum client configuration file under /etc/yum.repos.d. Enter the following details.

yum client
For running group commands like grouplist, groupinstall we need to copy *-comps-Server.x86_64.xml and using this file we need to update the metadata again using the following commands.
# cd /var/ftp/pub/rhel7/dvd/repodata/
# cp 76a190afa1c59e14d3a03f9b03c3eee31df0099f1193528ebb87d4d493d2b686-comps-Server.x86_64.xml /var/ftp/pub/rhel7/dvd/group-comps-Server.x86_64.xml
# createrepo -vg /var/ftp/pub/rhel7/dvd/group-comps-Server.x86_64.xml /var/ftp/pub/rhel7/dvd/
yum group files

Test the yum configuration and yum group file settings using yum grouplist command.
yum grouplist
Now install the Kickstart packages using YUM for configuring the kickstart input file.
yum install kickstart
Install Apache software into this server using YUM .
 # yum install httpd
 apache installation
Now create a soft link of /var/ftp/pub into /var/www/html directory so that you can access this repository and installation tree using FTP or HTTP Protocol.
# ln -s /var/ftp/pub/ /var/www/html/Update the SELINUX context for these directory using restorecon command.
# restorecon -Rv /var/ftp/pub/
# restorecon -Rv /var/www/html/
Start the service for vsftpd and httpd using following commands.
#systemctl start vsftpd
#systemctl start httpd
#systemctl enable vsftpd
#systemctl enable httpd
enabling services
Note: there is no firewalld and SELINUX running in my server.
Now create a kickstart file for unattended installation of RHEL 7.0 OS. to create kickstart unattended file run # system-config-kickstart utility. now you could see a window similar to the below. provide the required information and save it under /var/ftp/pub directory.
kickstart utility
Another way to create kickstart file to copy the /root/anaconda-ks.cfg file to /var/ftp/pub and edit according to your requirement. Here is my kickstart file.

Now restart the vsftp and httpd services.
# systemctl restart vsftpd
# systemctl restart httpd
restart ftp and httpd
Check whether you are able to access the ks.cfg using http. use firefox or links to check it.
# links
if its successful then you will get this screen.
ks.cfg links
Now we need to install the packages for PXE boot. Install syslinux, xinetd, tftp-server and dhcp using YUM.
# yum install syslinux xinetd tftp-server dhcp -y
pxe packages
create a directory pxe configuration directory named "pxelinux.cfg" in /var/lib/tftpboot.
 # mkdir /var/lib/tftpboot/pxelinux.cfg
pxelinux cfg directory
Now copy the "/usr/share/syslinux/pxelinux.0" to /var/lib/tftpboot directory.
# cp /usr/share/syslinux/pxelinux.0 /var/lib/tftpboot/
pxe boot kernel
Enable tftp service. edit the /etc/xinetd.d/tftp file and enable the xinetd configuration. this is used to provide pxe kernel to client.
tftp enable
Start and enable tftp server (xinetd) service. run the following commands.
# systemctl start xinetd
# systemctl enable xinetd
xinetd service startup
Now configure DHCP service . More information on DHCP server configuration please click here.
This is used to give the IP address to clients. To configure DHCP copy the sample configuration from /usr/share/doc/dhcp-4.2.5/dhcpd.conf.example to /etc/dhcp/dhcpd.conf

# cp /usr/share/doc/dhcp-4.2.5/dhcpd.conf.example /etc/dhcp/dhcpd.conf

dhcp client configuration
Now edit the configuration file /etc/dhcp/dhcpd.conf and add the following lines.
allow booting;
allow bootp;

# This is a very basic subnet declaration.

subnet netmask {
  option routers;
  default-lease-time 21600;
  max-lease-time 43200;

# This declaration allows BOOTP clients to get dynamic addresses,
# which we don't really recommend.

subnet netmask {
  range dynamic-bootp;
  option broadcast-address;
  option routers;
  option domain-name "";
  default-lease-time 21600;
  max-lease-time 43200;
  filename "pxelinux.0";

dhcp server config
Restart the dhcpd service and enabled it using the following command.
# systemctl restart dhcpd
# systemctl enable dhcpd
dhcp service restart
Now copy the following files from RHEL 7.0 to /var/lib/tftpboot/ for creating the PXE server.
# cd /var/ftp/pub/rhel7/dvd/images/pxeboot/
# cp initrd.img /var/lib/tftpboot/
# cp vmlinuz /var/lib/tftpboot/
# cp /usr/share/syslinux/menu.c32 /var/lib/tftpboot/
# cd /var/ftp/pub/rhel7/dvd/isolinux/
# cp -rvf * /var/lib/tftpboot/

pxe files copied
Now create a PXE boot menu. create a file named "default" under /var/lib/tftpboot/pxelinux.cfg directory. and add the following lines.
default vesamenu.c32
timeout 600
display boot.msg
menu background splash.png


label linux
  menu label ^Install System from PXE
  kernel vmlinuz
  append initrd=initrd.img ks= ksdevice=eno16777736 ip=dhcp

label local
  menu label Boot from ^local drive
  localboot 0xffff

pxe boot menu
Now restart the vsftpd , httpd and httpd service and not boot the client and check the configuration.
You could see a below screen in the PXE client machine.
pxe client menu
select it and you would see that it start installing the RHEL7.0 os on the client.
os installation
Thats all about the PXE server configuration. Hope you found this useful.

1 comment:

  1. This is great documentation work..thank you