PXE（Preboot Excution Environment）： 预启动执行环境，Intel公司研发，基于Client/Server的网络模式，支持远程主机通过网络从远端服务器下载映像，并由此支持通过网络启动操作系统。 PXE可以引导和安装Windows,linux等多种操作系统
PXE工作原理： 客户端向PXE服务器上的dhcp服务发送IP地址请求消息，dhcp服务检测客户端请求是否合法，主要是检测客户机的网卡MAC地址，如果合法则分配给客户端IP地址，同时将启动文件名pxelinux.0和启动文件位置信息一并传送给客户端。 客户端向PXE 服务器上的tftp服务发送获取启动文件pxelinux.0请求消息，tftp服务在接收到消息之后向客户端发送pxelinux.0大小信息，询问客户端是否同意使用，当tftp服务收到客户端发回的同意使用信息之后，正式向客户端发送pxelinux.0文件。 客户端执行接收到的pxelinux.0文件。 客户端向tftp服务器发送针对本机的配置信息文件（在tftp 服务器的pxelinux.cfg目录下），tftp服务器将配置文件发回客户端，继而客户端根据配置文件执行后续操作。 客户端向tftp服务器发送Linux内核请求信息，tftp服务器在接收到消息之后将内核文件发送给客户端 客户端向tftp服务器发送根文件请求信息，tftp服务器接收到消息之后返回Linux根文件系统给客户端。 客户端启动Linux内核，下载安装源文件，读取自动化安装脚本环境准备：
关闭防火墙
systemctl stop firewalld.service systemctl disable firewalld.servicesystemctl stop iptables
systemctl disable iptables关闭selinux
setenforce 0 vim /etc/selinux/config修改SELINUX=disabled设置静态IP
vim /etc/sysconfig/network-scripts/ifcfg-ens33
1 TYPE=Ethernet 2 BOOTPROTO=static #网络协议 3 NAME=ens33 4 UUID=c7c0aaf8-2a87-4217-819b-fdbc1d08a7e8 5 DEVICE=ens33 6 ONBOOT=yes #开机启动 7 DNS1=114.114.114.114 8 DNS2=8.8.8.8 9 IPADDR=192.168.121.1010 NETMASK=255.255.255.011 GATEWAY=192.168.121.2
安装相关软件包
yum install -y dhcp tftp-server httpd syslinux
启动httpd服务
systemctl enable httpd systemctl start httpdcp /etc/xinetd.d/tftp /etc/xinetd.d/tftp.bak
vim /etc/xinetd.d/tftp
1 service tftp 2 { 3 socket_type = dgram 4 protocol = udp 5 wait = yes 6 user = root 7 server = /usr/sbin/in.tftpd 8 server_args = -s /var/lib/tftpboot 9 disable = no 10 per_source = 11 11 cps = 100 2 12 flags = IPv4 13 } 启动tftpd服务
systemctl enable tftp.socket systemctl start tftp.socketcp -f /usr/share/doc/dhcp*/dhcpd.conf.example /etc/dhcp/dhcpd.conf.bak
vim /etc/dhcp/dhcpd.conf
1 ddns-update-style interim; 2 ignore client-updates; 3 subnet 192.168.121.0 netmask 255.255.255.0 { 4 5 option routers 192.168.121.2; 6 option subnet-mask 255.255.255.0; 7 8 filename "pxelinux.0"; 9 next-server 192.168.121.10;10 range dynamic-bootp 192.168.121.11 192.168.121.100;11 default-lease-time 21600;12 max-lease-time 43200;13 } 启动dcpd服务
systemctl enable dhcpd
systemctl start dhcpd制作centos7和centos6的安装源文件
mkdir -pv /var/www/html/centos/{6,7}
mkdir -pv /media/cdrom{6,7}mount /dev/sr0 /media/cdrom6/
cp /media/cdrom6 /* /var/www/html/centos/6/ -r mount /dev/sr1 /media/cdrom7/ cp /media/cdrom7/* /var/www/html/centos/7/ -r制作centos6和centos7的kickstart文件
修改anaconda.cfg文件,此文件会在每次装完系统后生成于/root/目录下.
使用system-config-kickstart命令生成（需要安装X Windows 和Desktop） yum groupinstall "X Window System" yum groupinstall Desktopmkdir /var/www/html/ksdir/
vim /var/www/html/ksdir/ks7-1.cfg1 #version=DEVEL 2 # System authorization information 3 auth --enableshadow --passalgo=sha512 4 # Use CDROM installation media 5 url --url=http://192.168.121.10/centos/7 6 # Use graphical install 7 graphical 8 # Run the Setup Agent on first boot 9 firstboot --enable10 ignoredisk --only-use=sda11 # Keyboard layouts12 keyboard --vckeymap=us --xlayouts='us'13 # System language14 lang en_US.UTF-815 16 # Network information17 network --bootproto=dhcp --device=ens33 --onboot=on --ipv6=auto --activate18 network --hostname=localhost.localdomain19 20 # Root password21 rootpw --iscrypted $6$SNhR8RU2Euwg1ydI$gPITLqKSRMfm11hIyaIqPbmRo579k7hhpsOp4cQRhBO/dEH8vWt2b4upxYiQEXKzgzS55FccpqcWiz/7/LL4w.22 # System timezone23 timezone Asia/Shanghai --isUtc --ntpservers=0.centos.pool.ntp.org24 # System bootloader configuration25 bootloader --append=" crashkernel=auto" --location=mbr --boot-drive=sda26 # Partition clearing information27 zerombr28 clearpart --all29 reboot30 # Disk partitioning information31 part /boot --fstype="xfs" --ondisk=sda --size=20032 part swap --fstype="swap" --ondisk=sda --size=2048 33 part / --fstype="xfs" --ondisk=sda --grow --size=1 34 35 36 %packages37 @^minimal38 @core39 kexec-tools40 41 %end42 43 %addon com_redhat_kdump --enable --reserve-mb='auto'44 45 %end46 47 %anaconda48 pwpolicy root --minlen=6 --minquality=1 --notstrict --nochanges --notempty49 pwpolicy user --minlen=6 --minquality=1 --notstrict --nochanges --emptyok50 pwpolicy luks --minlen=6 --minquality=1 --notstrict --nochanges --notempty51 %end52 53 %post54 systemctl restart network.service55 yum install vim wget net-tools xorg-x11-xauth screen -y56 cd /etc/yum.repos.d/57 rm -rf *58 wget -c http://mirrors.163.com/.help/CentOS7-Base-163.repo59 systemctl disable firewalld.service60 cp /etc/sysconfig/network-scripts/ifcfg-ens33 /etc/sysconfig/network-scripts/ifcfg-ens33.bak61 sed -i 's/dhcp/static/g' /etc/sysconfig/network-scripts/ifcfg-ens33.bak62 echo 'IPADDR=192.168.121.121'>> /etc/sysconfig/network-scripts/ifcfg-ens33.bak63 echo 'NETMASK=255.255.255.0'>> /etc/sysconfig/network-scripts/ifcfg-ens33.bak64 echo 'GATEWAY=192.168.121.2'>> /etc/sysconfig/network-scripts/ifcfg-ens33.bak65 echo 'DNS1=114.114.114.114' >> /etc/sysconfig/network-scripts/ifcfg-ens33.bak66 sed -i 's/enforcing/disabled/g' /etc/selinux/config67 %end
vim /var/www/html/ksdir/ks6-1.cfg
1 #version=DEVEL 2 install 3 url --url=http://192.168.121.10/centos/6 4 lang en_US.UTF-8 5 keyboard us 6 network --onboot yes --device eth0 --bootproto dhcp --noipv6 7 rootpw --iscrypted $6$55ArpbZ9EoUhTKt5$pYnhDc2zbpdOt1aR4rIf7keHxy0aZ7hi/C.1XmLV5IOpYgkv5zTC61trhk3oDfDocracX6CtpBx2kZ7frHvP0. 8 firewall --service=ssh 9 authconfig --enableshadow --passalgo=sha51210 selinux --enforcing11 timezone Asia/Shanghai12 bootloader --location=mbr --driveorder=sda --append="crashkernel=auto rhgb quiet"13 # The following is the partition information you requested14 # Note that any partitions you deleted are not expressed15 # here so unless you clear all partitions first, this is16 # not guaranteed to work17 zerombr18 clearpart --all19 reboot20 part /boot --fstype=ext4 --size=20021 part swap --size=200022 part / --fstype=ext4 --grow --size=20023 24 #repo --name="CentOS" --baseurl=cdrom:sr0 --cost=10025 26 %packages27 @core28 %end29 30 %post31 service network restart 32 yum install vim wget net-tools -y33 cd /etc/yum.repos.d/34 rm -rf *35 wget -c http://mirrors.163.com/.help/CentOS6-Base-163.repo36 chkconfig iptables off37 cp /etc/sysconfig/network-scripts/ifcfg-ens33 /etc/sysconfig/network-scripts/ifcfg-ens33.bak38 sed -i 's/dhcp/static/g' /etc/sysconfig/network-scripts/ifcfg-ens33.bak39 echo 'IPADDR=192.168.121.121'>> /etc/sysconfig/network-scripts/ifcfg-ens33.bak40 echo 'NETMASK=255.255.255.0'>> /etc/sysconfig/network-scripts/ifcfg-ens33.bak41 echo 'GATEWAY=192.168.121.2'>> /etc/sysconfig/network-scripts/ifcfg-ens33.bak42 echo 'DNS1=114.114.114.114' >> /etc/sysconfig/network-scripts/ifcfg-ens33.bak43 sed -i 's/enforcing/disabled/g' /etc/selinux/config44 %end
检验ks文件
yum install system-config-kickstart -y
ksvalidator /var/www/html/ksdir/ks7-1.cfg ksvalidator /var/www/html/ksdir/ks6-1.cfg制作PXE相关文件
mkdir /var/lib/tftpboot/centos{6,7}
mkdir /var/lib/tftpboot/pxelinux.cfg/cp /usr/share/syslinux/{pxelinux.0,menu.c32} /var/lib/tftpboot/
cp /var/www/html/centos/7/isolinux/{initrd.img,vmlinuz} /var/lib/tftpboot/centos7 cp /var/www/html/centos/6/isolinux/{initrd.img,vmlinuz} /var/lib/tftpboot/centos6 cp /var/www/html/centos/7/isolinux/isolinux.cfg /var/lib/tftpboot/pxelinux.cfg/defaulttree /var/lib/tftpboot/
/var/lib/tftpboot/ ├── centos6 │ ├── initrd.img │ └── vmlinuz ├── centos7 │ ├── initrd.img #伪文件系统文件 │ └── vmlinuz #内核文件 ├── menu.c32 #纯文本菜单 ├── pxelinux.0 #引导文件，相当于grub。 └── pxelinux.cfg └── default #启动菜单文件制作启动菜单
vim /var/lib/tftpboot/pxelinux.cfg/default1 default menu.c32 2 timeout 600 3 menu title CentOS Linux PXE Install 4 5 label centos7 #自动安装centos7 6 menu label Auto Install CentOS Linux ^7 7 menu default #默认启动项 8 kernel centos7/vmlinuz 9 append initrd=centos7/initrd.img ks=http://192.168.121.10/ksdir/ks7-1.cfg #应答文件所在路径10 11 label centos6 #自动安装centos612 menu label Auto Install CentOS Linux ^613 kernel centos6/vmlinuz14 append initrd=centos6/initrd.img ks=http://192.168.121.10/ksdir/ks6-1.cfg15 16 label manual7 #手动安装centos717 menu label ^Manual Install CentOS Linux 718 kernel centos7/vmlinuz19 append initrd=centos7/initrd.img inst.repo=http://192.168.121.10/centos/720 21 label manual6 #手动安装centos622 menu label Manual ^Install CentOS Linux 623 kernel centos6/vmlinuz24 append initrd=centos6/initrd.img inst.repo=http://192.168.121.10/centos/625 26 label local #本地硬盘启动27 menu label Boot from ^local drive28 localboot 0xffff29 menu end