首先替换默认源为163源:
	mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
	wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
	mv CentOS6-Base-163.repo /etc/yum.repos.d/
	 
	升级系统:
	yum makecache
	yum update
	 
	升级过程中报了一个key相关的错误,具体记不清了,重新执行yum update确定导入key即可。
	 
	重启,确认更新成功:
	 
	[root@localhost ~]# uname -r
	2.6.32-220.7.1.el6.x86_64
	[root@localhost ~]# cat /etc/RedHat-release
	CentOS release 6.2 (Final)

