How to Build a PXE‑Kickstart Unattended Installation Server on CentOS 7

1. Required Services Overview

PXE : Remote boot technology that allows a computer to start via network.

Kickstart : Unattended OS deployment using an answer file.

TFTP : Simple file transfer protocol (port 69) used to share PXE boot files.

DHCP : Assigns IP addresses to client machines.

FTP : Shares ISO images and the Kickstart answer file.

2. Experiment Setup

All services (FTP, DHCP, TFTP) are deployed on a single server (qll251, CentOS 7 with dual NICs 192.168.1.251 and 192.168.2.251). The client machine (qll252) uses the LAN1 network.

Requirements:

Disable firewall and SELinux.

Ensure yum can install packages (local or remote repository).

3. Deploy Services

3.1 Install and start FTP

[root@qll251 ~]# yum -y install vsftpd</code><code>[root@qll251 ~]# systemctl start vsftpd</code><code>[root@qll251 ~]# systemctl enable vsftpd

Shared path:

/var/ftp

3.2 Install and configure DHCP

[root@qll251 ~]# yum -y install dhcp</code><code>[root@qll251 ~]# vim /etc/dhcp/dhcpd.conf</code><code>[root@qll251 ~]# systemctl start dhcpd</code><code>[root@qll251 ~]# systemctl enable dhcpd

Typical configuration assigns IPs to PXE clients.

3.3 Install and configure TFTP

[root@qll251 ~]# yum -y install tftp-server</code><code>[root@qll251 ~]# yum -y install xinetd</code><code>[root@qll251 ~]# systemctl start tftp && systemctl enable tftp</code><code>[root@qll251 ~]# systemctl start xinetd && systemctl enable xinetd

Shared directory:

/var/lib/tftpboot

3.4 Prepare PXE boot files

[root@qll251 ~]# yum -y install syslinux</code><code>[root@qll251 ~]# cp /usr/share/syslinux/pxelinux.0 /var/lib/tftpboot/</code><code>[root@qll251 ~]# cp /media/images/pxeboot/initrd.img /var/lib/tftpboot/</code><code>[root@qll251 ~]# cp /media/images/pxeboot/vmlinuz /var/lib/tftpboot/</code><code>[root@qll251 ~]# mkdir /var/lib/tftpboot/pxelinux.cfg</code><code>[root@qll251 ~]# cp /media/isolinux/isolinux.cfg /var/lib/tftpboot/pxelinux.cfg/default</code><code>[root@qll251 ~]# chmod 644 /var/lib/tftpboot/pxelinux.cfg/default

Edit /var/lib/tftpboot/pxelinux.cfg/default to include:

default linux</code><code>label linux</code><code>  menu label ^Install CentOS 7</code><code>  kernel vmlinuz</code><code>  append initrd=initrd.img inst.repo=ftp://192.168.2.251/pub inst.ks=ftp://192.168.2.251/ks.cfg

3.5 Create Kickstart answer file

[root@qll251 ~]# yum -y install system-config-kickstart</code><code># Run the graphical tool</code><code>system-config-kickstart

Save the generated ks.cfg to /var/ftp/ks.cfg. Ensure the ISO files are copied to /var/ftp/pub:

# cp -r /media/* /var/ftp/pub

4. Prepare PXE Boot Files

Mount the installation ISO: [root@qll251 ~]# mount /dev/sr0 /media Share the following via FTP:

/var/ftp/ks.cfg

All files from the mounted ISO (copied to /var/ftp/pub)

Share the following via TFTP:

pxelinux.0

initrd.img

vmlinuz

pxelinux.cfg/default (modified as above)

5. Execute Batch Installation

Set client BIOS to boot from network (or press F12 at startup).

The client will download the PXE configuration, retrieve the kernel and initrd via TFTP, then fetch the installation source and Kickstart file via FTP, performing a fully automated installation without manual intervention.

After installation, log in with the predefined root password; the test script “hello world” runs, and the client receives IP 192.168.2.3.