PXE principle and configuration

Catalog

PXE Introduce

PXE Service construction process

To configure PXE

verification

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PXE Introduce

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 .

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  

To configure PXE

First disable the firewall

systemctl stop firewalld

systemctl disable firewalld

setenforce 0

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

Then check whether the addition is successful , One more. ens37 It means that the addition is successful

And then to ens37 Configure network card directory

cd /etc/sysconfig/network-scripts  # Enter the network card configuration directory

cp ifcfg-ens33 ifcfg-ens37

vim ifcfg-ens37

Get into ens37 To put uuid Delete , Otherwise, it will bump out bug

ip The address should be net1 In segment , The gateway can be configured without

After configuration ,systemctl restart network Restart the network card service

then yum install dhcp service , Installed ones can also yum Upgrade next

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 , Whether to overwrite the input y Express yes

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

From top to bottom, it means ：

Disable dynamic updates

Network segment

Address pool

gateway

dns Address

Appoint tftp Server address

Appoint pxe The file name of the bootloader

Last systemctl start dhcpd     # Turn on dhcp service

systemctl enable dhcpd    # Boot up

yum -y install tftp-server    

yum -y install xinetd

{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 }

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

Only need to disable Change that line to no that will do （ double negative , Open for indication tftp service ）

mount /dev/cdrom / Empty directory           Mount the image file

df -Th Check whether the mount is successful

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

Last systemctl start xinetd        Opening service

systemctl enable xinetd

systemctl start tftp

systemctl enable tftp

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

cp Copy the second

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

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

（ There is no need to add the following ks=ftp：//192.168.100.111/ks.cfg）

install ftp service , Get ready centos7 Installation source

yum -y install vsftpd   # install ftp service

mkdir /var/ftp/centos7   

cp -rf /mnt/* /var/ftp/centos7   # Copy the image to it

Last systemctl start vsftpd # Turn on ftp service

systemctl enable  vsftpd  # Boot from boot  

yum -y install system-config-kickstart       # install system-config-kickstart Tools

Enter the application in the upper left corner of the desktop , Select system tools , choice kickstart, Then set it step by step

 

Save the configuration to /var/ftp in , Change of name ks.cfg

ls Look at the file

cd /root  # Enter home directory

vim anaconda-ks.cfg   

Put the following figure inside , Copied to the var/ftp/ks.cfg in

 

After copying and pasting cat /var/ftp/ks.cfg Check it out.

vim /var/lib/tftpboot/pxelinux.cfg/default 

# Enter the menu file to optimize , take ks Boot parameters to boot menu file

Now the configuration is complete

verification

Create an empty virtual machine , Don't give the image file

  Then start the virtual machine and let it install automatically