为启动加密码：
grub-md5-crypt
Password: <==输入密码
Retype password: <==再输入一次
$1$6kWUD1$AIZWzT3Ye6CAF0aYceWxr1
复制这个MD5密码
vim /boot/grub/menu.lst
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
# initrd /initrd-version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux Server (2.6.18-164.el5)
password --md5 $1$6kWUD1$AIZWzT3Ye6CAF0aYceWxr1
root (hd0,0)
kernel /vmlinuz-2.6.18-164.el5 ro root=/dev/VolGroup00/LogVol00 rhgb qui
et
initrd /initrd-2.6.18-164.el5.img
说明：此项功能还是可以破解的，因为用户可以通过编辑模式（e）进入菜单，按（d）删除密码字段并按下b就能通过启动流程
这样可以避免：
vim /boot/grub/menu.lst
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
# initrd /initrd-version.img
#boot=/dev/sda
default=0
timeout=5
password --md5 $1$6kWUD1$AIZWzT3Ye6CAF0aYceWxr1
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux Server (2.6.18-164.el5)
password --md5 $1$6kWUD1$AIZWzT3Ye6CAF0aYceWxr1
root (hd0,0) kernel /vmlinuz-2.6.18-164.el5 ro root=/dev/VolGroup00/LogVol00 rhgb qui
et
initrd /initrd-2.6.18-164.el5.img
这个实验可以避免你的menu.lst在启动过程中被改乱