生成grub密码，防止陌生人进入单用户模式

• 非明文密码生成

grub-crypt
# 生成sha加密方式的密码
grub-crypt --md5
# 生成md5加密方式的密码

• 配置

  将生成的密码粘贴到/etc/grub.conf中，格式如下（password位置）：

# 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/sda3
#          initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
# 此处为加密的密码，--sha和--md5用来说明加密方式
password --sha $6$vRBcWIqOLylJpTex$v80lPovSU/F5C.tpDM5zQbhYJjHGFSlAHhFC.7cEBHiBqA3W/v/HGbasdxFBWNyOdWGQ.3Wzxi4mBgmAOpRes1
title CentOS 6 (2.6.32-573.el6.x86_64)
        root (hd0,0)
        kernel /vmlinuz-2.6.32-573.el6.x86_64 ro root=UUID=94f2979f-d553-4ffa-ba52-fc2a84e00312 nomodeset rd_NO_LUKS  KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_NO_LVM rd_NO_DM rhgb quiet
        initrd /initramfs-2.6.32-573.el6.x86_64.img

来自为知笔记(Wiz)