方法1：改动/etc/inittab
屏蔽
ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now
或者删除改行内容

保存退出
适用对象：RedHat4.8 RedHat 5.4 RedHat 5.5

方法2：改动/etc/init/control-alt-delete.conf
编辑/etc/init/control-alt-delete.conf
屏蔽
start on control-alt-delete
exec /sbin/shutdown -r now "Control-Alt-Delete pressed"

保存退出
或者另存改文档{建议在shell脚本中使用以下方法}

#\mv /etc/init/control-alt-delete.conf /etc/init/control-alt-delete.conf.bak

适用对象：RedHat 6.X,CentOS 6.x