CentOS pxe（DHCP+TFTP+NFS+kickstart）网络安装

1 Pxe安装原理

无论安装什幺类型的操作系统，PXE的安装过程大致可以描述为以下几个步骤:

客户机从自己的PXE网卡启动，向本网络中的DHCP服务器索取IP ，客户机向本网络中的TFTP服务器索取bootstrap文件，客户机取得bootstrap文件后之执行该文件，根据bootstrap的执行结果，通过TFTP服务器加载内核和文件系统进入安装画面, 此时可以通过选择FTP,HTTP,NFS方式之一进行安装从这里我们不难得到实现PXE网络安装必需的4个要素

客户机的网卡必须为PXE网卡

网络中必须要有DHCP和TFTP服务器，当然这两个服务器可以是同一台物理主机，所安装的操作系统必须支持网络安装，即必须提供自己的bootstrap

必须要有FTP,HTTP,NFS至少一个服务器，当然也可以和DHCP和TFTP服务器同为一台物理主机

2 Pxe安装启动图例



3 软件包环境

[root@localhost iso]# rpm -qa|grep dhcp

dhcp-3.0.5-23.el5_6.4

[root@localhost iso]# rpm -qa|grep nfs

nfs-utils-1.0.9-42.el5

system-config-nfs-1.3.23-1.el5

nfs-utils-lib-1.0.8-7.6.el5

[root@localhost iso]# rpm -qa|grep tftp

tftp-0.49-2.el5.centos

tftp-server-0.49-2.el5.centos（务必安装）

采用yum方式安装

4 Dhcp配置

指定安装端

[root@localhost ~]# vi /etc/dhcpd.conf

ddns-update-style interim;

ignore client-updates;

filename "pxelinux.0"; --制定bootstrap文件，默认是tftp的主目录（/tftpboot）

subnet 192.168.15.0 netmask 255.255.255.0 {

# --- default gateway

option routers 192.168.15.101;

option subnet-mask 255.255.255.0;

option nis-domain "domain.org";

option domain-name "domain.org";

option domain-name-servers 192.168.15.101;

option time-offset -18000; # Eastern Standard Time

# option ntp-servers 192.168.1.1;

# option netbios-name-servers 192.168.1.1;

# --- Selects point-to-point node (default is hybrid). Don't change this unless

# -- you understand Netbios very well

# option netbios-node-type 2;

range dynamic-bootp 192.168.15.100 192.168.15.149;

default-lease-time 21600;

max-lease-time 43200;

# we want the nameserver to appear at a fixed address

group pxe {

host centos5.4_text{

next-server 192.168.15.101; --指明tftpserver的地址

hardware ethernet 00:0C:29:81:CE:8E; --此地址与客户端网卡地址保持一致，也可不分配IP和MAC地址

fixed-address 192.168.15.148;

}

}

}

未指定安装端

[root@localhost iso]# vi /etc/dhcpd.conf

ddns-update-style interim;

ignore client-updates;

filename "pxelinux.0";

next-server 192.168.15.101;

subnet 192.168.15.0 netmask 255.255.255.0 {

ddns-update-style interim;

ignore client-updates;

filename "pxelinux.0";

next-server 192.168.15.101;

subnet 192.168.15.0 netmask 255.255.255.0 {

# --- default gateway

option routers 192.168.15.101;

option subnet-mask 255.255.255.0;

option nis-domain "domain.org";

option domain-name "domain.org";

option domain-name-servers 192.168.15.101;

option time-offset -18000; # Eastern Standard Time

# option ntp-servers 192.168.1.1;

# option netbios-name-servers 192.168.1.1;

# --- Selects point-to-point node (default is hybrid). Don't change this unless

# -- you understand Netbios very well

# option netbios-node-type 2;

range dynamic-bootp 192.168.15.100 192.168.15.200;

default-lease-time 21600;

max-lease-time 43200;

# we want the nameserver to appear at a fixed address

host ns {

# next-server 192.168.15.101;

hardware ethernet 12:34:56:78:AB:CD;

fixed-address 192.168.15.119;

}

}

注：next-server 192.168.15.101;要写在前面,不能在host ns 内，hardware Ethernet和fixed-address默认文件配置的，可不予理睬！安装完成后IP为（ range dynamic-bootp 192.168.15.100 192.168.15.200）随机获得的IP地址。

5 Tftp配置

[root@localhost ~]# vi /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.

service tftp

{

disable = no

socket_type = dgram

protocol = udp

wait = yes

user = root

server = /usr/sbin/in.tftpd

server_args = -u nobody -s /tftpboot

per_source = 11

cps = 100 2

flags = IPv4

6 nfs配置

1) 编辑NFS服务器配置文件 /etc/exports，以允许其它机器通过NFS访问目录/madia/rhel4,文件内容如下：

#vi /etc/exports

/iso/ *(ro) --镜像文件解压后放置此处

/tftpboot/ *(ro)

2) 重新启动NFS服务以使新配置生效

# service portmap restart

# service nfs restart

7 制作linux内核、跟文件系统

将/usr/lib/syslinux/下的启动镜像文件pxelinux.0拷到TFTP服务器/tftpboot/ 下

#cp /usr/lib/syslinux/pxelinux.0 /tftpboot/

将/isolinux/下的isolinux.cfg复制到TFTP服务/tftpboot/pxelinux.cfg/下：

#cp /media/rhel4/isolinux/isolinux.cfg /tftpboot/pxelinux.cfg/default

将/isolinux/下的所有名为.msg文件、vmlinuz文件 、initrd.img文件拷到TFTP服务器/tftpboot/ /下：

#cp /iso/isolinux/*.msg /tftpboot/

#cp /iso/isolinux/vmlinuz /tftpboot/

#cp /iso/isolinux/initrd.img /tftpboot/

/tftpboot/linux-install/pxelinux.cfg/default此文件可以默认不用配置，但也可以修改,

到此手动安装已完成，pxe启动客户端，进入boot选择网络安装，然后选择nfs服务器指定其目录进行安装