简单原理介绍：无光软驱服务器通过PXE网卡启动，从dhcp服务器获取IP 通过tftp 下载pxelinux.0文件找到pxelinux.cfg里的配置文件，按配置文件找着vmlinuz引导CentOS进入安装界面，之后选择NFS方式安装系统。
另： 如需要实现全自动安装 要安装 Kickstart 软件包并配置。本文并不讨论
二、环境说明
本文测试环境及用到的软件
Server: centos 5.2 dhcp nfs tftp ip:192.168.1.251 (此IP只需要与服务器网卡相连，不管是什么都可以)
三、安装配置过程及基本讲解：
安装相应的软件：yum –y install dhcp* nfs* tftp*
1、 配置tftp more /etc/xinetd.d/tftp
# default: off
# description: The tftp server serves files using the trivial file transfer \
# protocol. The tftp protocol is often used to boot diskless \
# workstations, download configuration files to network-aware printers, \
# and to start the installation process for some operating systems.
# trad: liuyu
# blog: liuyu.blog.51cto.com
# bbs:
service tftp
{
disable = no #默认是yes 改为no
socket_type = dgram
protocol = udp
wait = yes
user = root
server = /usr/sbin/in.tftpd
server_args = -u nobody -s /tftpboot #添加nobody可以访问
per_source = 11
cps = 100 2
flags = IPv4
}
复制代码重启xinetd服务： /etc/init.d/xinetd restart
查看tftp 是否启动：# chkconfig --list |grep tftp
tftp: on
2、 配置nfs
mount /iso/CentOS-5.2-i386-bin-1of6.iso /mnt -o loop #我是挂载的镜像文件，你们可以挂载光驱
echo "/tftpboot *(ro,sync)" > /etc/exports
echo "/mnt *(ro,sync)" > /etc/exports #此二步设置共享的目录
exportfs –a #使配置生效
/etc/init.d/portmap start &&/etc/init.d/nfs start #重启服务
Showmount –e localhost #看查共享的目录
Export list for localhost:
/mnt *
/tftpboot *
3、配置dhcp
直接copy我的配置
# more /etc/dhcpd.conf
#
# DHCP Server Configuration file.
# see /usr/share/doc/dhcp*/dhcpd.conf.sample
#
# trad: liuyu
# blog: liuyu.blog.51cto.com
# bbs:
ddns-update-style interim;
ignore client-updates;
allow booting;
allow bootp;
subnet 192.168.1.0 netmask 255.255.255.0 {
option routers 192.168.1.251;
option subnet-mask 255.255.255.0;
option domain-name-servers 192.168.1.251; #本地IP
option time-offset -18000; # Eastern Standard Time
range dynamic-bootp 192.168.1.12 192.168.1.254; #要分区的IP
default-lease-time 21600;
max-lease-time 43200;
# Group the PXE bootable hosts together
# PXE-specific configuration directives...
next-server 192.168.1.251;
filename "/pxelinux.0"; #方便查找配置文件
}
复制代码/etc/init.d/dhcpd start 启动服务