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PXE By intel Network guidance technology developed by the company , Work again C/S In mode , Allows clients to download boot images from remote servers over the network , And load the installation file or the whole system .

PEX Strictly speaking, it is not an installation method , It's a way of guiding . Conduct PXE The necessary condition for installation is that the installed computer contains a PXE Supported network cards （NIC）, That is, there must be PXE Client. PXE The protocol enables the computer to start over the network .

The agreement is divided into client and server End ,PEX client On the network card ROM in , When the computer boots ,BIOS hold PXE client Call in memory to execute , from PXE client Download the files placed at the remote end to run locally through the network . function PXE The protocol needs to be set DHCP The server and TFTP The server .DHCP The server is used for PXE client Allocate one IP, Because it's for PXE client Allocation address , So in configuration DHCP The server needs to add what you want PXE Set up .

Two 、PXE Service construction process

1、PXE The client sends DHCP request , towards DHCP Server application IP Address .

2、DHCP Server response PXE Client requests , Automatically from IP Allocate an address in the address pool IP Address to PXE The client , And tell PXE The client ：TFTP Server's IP Address and PXE Bootloader file pxelinux.0, Default in TFTP share directory /var/lib/tftoboot Next

3、PXE The client is going to TFTP The server initiates the acquisition pxelinux.0 Request for bootstrap file .

4、TFTP Server response PXE Client requests , Share it pxelinux.0 File transfer to PXE The client .

5、PXE The client starts to the main interface of system installation through the network

6、PXE Client to file sharing server （ftp、http、nfs） Initiate acquisition centos System or windows Request for system installation files .

7、vsftp File sharing service response PXE request , Transfer the shared quota system installation file to PXE The client .

8、PXE The client enters the installation prompt wizard interface , Users need to manually complete the operation of system installation

3、 ... and 、 Start configuration PXE

3.1、 Turn off firewall and core firewall

systemctl stop firewalld
systemctl disable firewalld
setenforce 0

3.2、 Environmental preparation

One function of configuring dual network cards is dhcp, A use network source installation environment package

dhcp Automatically assigned IP Your network card must be net1 Host only mode

ifconfig Check the network card information

cd /etc/sysconfig/network-scripts # Enter the network card configuration directory
cp ifcfg-ens33 ifcfg-ens36
vim ifcfg-ens36

We need to check it before changing net1 Network segment of network card

So we configure the network card in this way

Restart the network card after configuration

systemctl restart network # Restart the network card service

3.3、 To configure dhcp service

yum -y install dhcp # install dhcp service

vim /etc/dhcp/dhcpd.conf # Go to configuration file

cp -p /usr/share/doc/dhcp*/dhcpd.conf.example /etc/dhcp/dhcpd.conf #-p Copy with file attributes

vim /etc/dhcp/dhcpd.conf # Go back to editing

systemctl start dhcpd # Turn on dhcp service
systemctl enable dhcpd # Boot up

3.4、 Install and configure tftp service

Before configuring, briefly talk about tftp,tftp Is a small and easy to implement file transfer protocol ,tftp Is based on UDP The datagram , We need to have our own corrective measures .tftp Only file transfer is supported , No interaction supported , There is no huge command set . Low security , Authentication is not supported

yum -y install tftp-server
yum -y install xinetd
#tftp By xinetd Escrow ,xinetd Not installed by default , The configuration file
rpm -q tftp-server xinetd # Check if the installation is successful

In this way, the installation is successful and the configuration can begin

vim /etc/xinetd.d/tftp # To configure tftp

The main change is disable This line , Turn on tftp service

3.5、 Get ready ftp Files that need to be shared

mount /dev/cdrom /mnt # Mount the image file

Enter the kernel file Copy the kernel initialization image file to /var/lib/tftpboot

cd /mnt/images/pxeboot
cp initrd.img vmlinuz /var/lib/tftpboot # Copy the kernel initialization file

vmlinuz： It's steerable 、 Compressed kernel

initrd.img： System initialization file

systemctl start xinetd # Opening service
systemctl enable xinetd
systemctl start tftp
systemctl enable tftp

The above is to convert the kernel file in the image + System initialization file , Throw it tftp In the default shared directory , So that the client can download and use .

3.6、 Get ready PXE Boot image file pxelinux.0

pxelinux.0 It's a binary , The main function is equivalent to the guidance of a system installation step , Guide the client how to install the system

yum provides /pxelinux.0
# Find out which installation package installed this file , Use when not a path and a package
yum -y install syslinux

rpm -ql syslinux | grep pxelinux.0 # lookup pxe The location of the bootstrap

Select the second file to copy ,

cp /usr/share/syslinux/pxelinux.0 /var/lib/tftpboot # Copy tftp Under the root directory of , System boot file

notes , Only installed system-config-kickstart software package , Just can have /usr/share/syslinux/ Directory and files in the directory

3.7、 Manual configuration default Menu file

The Startup menu is used to know the boot process of the client , Including how to call the kernel , How to load drivers . Default

mkdir /var/lib/tftpboot/pxelinux.cfg/
# Default pxelinux.cfg There is no need to manually create , Note that it is a directory, not a directory .cfg ending
vim /var/lib/tftpboot/pxelinux.cfg/default # Configure menu file