一、实验目的
利用u盘引导实现无人值守安装CentOS系统，解决系统管理员因服务器无自带光驱的情况下实现u盘引导安装，同时安装系统过程利用网络HTTP网络服务提供安装文件，以达到全程无人值守安装。
二、实验准备
首先需参考光盘里的启动文件，利用启动文件构建一个启动u盘
[root@CentOS6 /mnt/cdrom/isolinux]#ls
boot.cat initrd.img memtest vesamenu.c32
boot.msg isolinux.bin splash.jpg vmlinuz
grub.conf isolinux.cfg TRANS.TBL
参考此目录文件制作u盘启动
[root@CentOS6 /mnt/cdrom/isolinux]#mkdir /app/myiso #创建存放光盘启动目录文件夹
[root@CentOS6 /mnt/cdrom/isolinux]#cp * /app/myiso/ #将当前目录下文件复制到myiso文件内
[root@CentOS6 /mnt/cdrom/isolinux]#cd /app/myiso/
[root@CentOS6 /app/myiso]#ls
boot.cat initrd.img memtest vesamenu.c32
boot.msg isolinux.bin splash.jpg vmlinuz
grub.conf isolinux.cfg TRANS.TBL
生成 .cfg文件，安装kickstart
# yum install system-config-kickstart
在桌面环境下配置Kickstart
system-config-kickstart
A. 设置语言，键盘，时区，Root密码，安装完毕后重启等。
1.png
B. 设置安装方式，这篇文章介绍的是HTTP方式的安装，故选择HTTP
1.png
C. 安装MBR
1.png
D.设置分区
1.png
E.配置网络
1.png
F. 认证配置
认证服务.png
G. SELinux 和防火墙配置
禁用防火墙.png
H. 图形环境配置
图形环境配置.png
I. 软件包安装选择
安装包.png
J.设置安装后运行脚本
设置安装后运行脚本.png
K.存盘退出
存盘退出.png
打开/var/www/html/ ks6-mini.cfg 文件进行查看并做修改
[root@CentOS7 /var/www/html/centos]#cat ks6-mini.cfg
#platform=x86, AMD64, or Intel EM64T
#version=DEVEL
# Firewall configuration
firewall --disabled
# Install OS instead of upgrade
install
# Use network installation
url --url="http://172.18.254.65/centos/6" ##这个选项告诉安装程序：到服务器172.18.254.65 的HTTP根目录下的cdrom 文件夹下寻找安装介质
# System authorization information
auth --useshadow --passalgo=sha512
# Use graphical install
graphical
firstboot --disable
# System keyboard
keyboard us
# System language
lang en_US
# SELinux configuration
selinux --disabled
# Installation logging level
logging --level=info
# System timezone
timezone Asia/Shanghai
# Network information
network --bootproto=dhcp --device=eth0 --onboot=on
# System bootloader configuration
bootloader --location=mbr
# Clear the Master Boot Record
zerombr
# Partition clearing information
clearpart --all --initlabel #此条命令必须添加，不然系统会让用户手动选择是否清除所有数据，这就需要人为干预了，从而导致自动化过程失败；
# Disk partitioning information
part /boot --fstype="ext4" --size=5000
part / --fstype="ext4" --size=20000
part swap --fstype="swap" --size=2048
%post
rm -rf /etc/yum.repos.d/*
cat > /etc/yum.repos.d/base.repo << EOF
[base]
baseurl=file:///mnt/cdrom
gpgcheck=0
EOF
useradd lai
echo magedu | passwd --stdin lai
%end
%packages
autofs
@core
@workstation-policy
@server-policy
vim
@base
%end
将要生成iso引导启动的isolinux.cfg文件进行修改，以此达到符合启动要求
1 default vesamenu.c32
2 #prompt 1
3 timeout 600
4
5 display boot.msg
6
7 menu background splash.jpg
8 menu title Welcome to CentOS 6.9 Automatic Install!
9 menu color border 0 #ffffffff #00000000
10 menu color sel 7 #ffffffff #ff000000
11 menu color title 0 #ffffffff #00000000
12 menu color tabmsg 0 #ffffffff #00000000
13 menu color unsel 0 #ffffffff #00000000
14 menu color hotsel 0 #ff000000 #ffffffff
15 menu color hotkey 7 #ffffffff #ff000000
16 menu color scrollbar 0 #ffffffff #00000000
17
18 label linux
19 menu label Install an ^Mini system
20 kernel vmlinuz
21 append initrd=initrd.img ks=http://172.18.254.65/ks6-mini.cfg #应答文件
22 label desktop
23 menu label Install an ^desktop system
24 kernel vmlinuz
25 append initrd=initrd.img ks=http://172.18.254.65/ks6-desktop.cfg #应答文件
26 label local
27 menu default
28 menu label Boot from ^local drive
29 localboot 0xffff
指定/app/myiso目录与文件制作成ISO 9660格式镜像文件
[root@CentOS6 /app]#mkisofs -R -J -T -v --no-emul-boot --boot-load-size 4 --boot-info-table -V "CentOS 6.9 x86_64 boot" -b isolinux/isolinux.bin -c 4 --boot-info-table -V "CentOS 6.9 x86_64 boot" -b isolinux/isolinux.bin -c isolinux/boot.cat -o /root/centos6_boot.iso /app/myiso/
I: -input-charset not specified, using utf-8 (detected in locale settings)
genisoimage 1.1.9 (Linux)
Scanning /app/myiso/
Scanning /app/myiso/isolinux
Excluded: /app/myiso/isolinux/TRANS.TBL
Excluded by match: /app/myiso/isolinux/boot.cat
Writing: Initial Padblock Start Block 0
Done with: Initial Padblock Block(s) 16
Writing: Primary Volume Descriptor Start Block 16
Done with: Primary Volume Descriptor Block(s) 1
Writing: Eltorito Volume Descriptor Start Block 17
Size of boot image is 4 sectors -> No emulation
Done with: Eltorito Volume Descriptor Block(s) 1
Writing: Joliet Volume Descriptor Start Block 18
Done with: Joliet Volume Descriptor Block(s) 1
Writing: End Volume Descriptor Start Block 19
Done with: End Volume Descriptor Block(s) 1
Writing: Version block Start Block 20
Done with: Version block Block(s) 1
Writing: Path table Start Block 21
Done with: Path table Block(s) 4
Writing: Joliet path table Start Block 25
Done with: Joliet path table Block(s) 4
Writing: Directory tree Start Block 29
Done with: Directory tree Block(s) 2
Writing: Joliet directory tree Start Block 31
Done with: Joliet directory tree Block(s) 2
Writing: Directory tree cleanup Start Block 33
Done with: Directory tree cleanup Block(s) 0
Writing: Extension record Start Block 33
Done with: Extension record Block(s) 1
Writing: The File(s) Start Block 34
21.93% done, estimate finish Fri Sep 15 10:59:56 2017
43.79% done, estimate finish Fri Sep 15 10:59:54 2017
65.71% done, estimate finish Fri Sep 15 10:59:53 2017
87.57% done, estimate finish Fri Sep 15 10:59:53 2017
Total translation table size: 4483
Total rockridge attributes bytes: 1360
Total directory bytes: 2048
Path table size(bytes): 26
Done with: The File(s) Block(s) 22658
Writing: Ending Padblock Start Block 22692
Done with: Ending Padblock Block(s) 150
Max brk space used 0
22842 extents written (44 MB)
[root@CentOS6 ~]#file centos6_boot.iso
centos6_boot.iso: ISO 9660 CD-ROM filesystem data 'CentOS 6.9 x86_64 boot' (bootable)
测试镜像能否正确引导
选择镜像文件.png
成功引导.png
安装成功
image.png
正确引导安装成功后，我们既可将引导镜像灌入至u盘
dd if=/dev/sr0 of=/dev/sdb
（注意：dd 后建议sync确保文件写入磁盘）