国内主机Debian6升级Debian7

手头一台国内的vps后台系统模板debian系只有6，只能升级自己升级到7了。如果不修改源升级的速度非常慢，于是将源改为国内源后升级成功，我用的是163的源。

修改源配置文件前先备份一下：

cd /etc/apt/sources.list /etc/apt/sources.list.bak

vi /etc/apt/sources.list编辑，清空原来内容再贴入以下源地址

deb http://mirrors.163.com/debian wheezy main non-free contrib
deb http://mirrors.163.com/debian wheezy-proposed-updates main contrib non-free
deb-src http://mirrors.163.com/debian wheezy main non-free contrib
deb-src http://mirrors.163.com/debian wheezy-proposed-updates main contrib non-free
deb http://mirrors.163.com/debian-security wheezy/updates main contrib non-free 
deb-src http://mirrors.163.com/debian-security wheezy/updates main contrib non-free 
#注释掉下面的三行，删除也行
#deb http://http.us.debian.org/debian wheezy main contrib non-free
#deb http://non-us.debian.org/debian-non-US wheezy/non-US main contrib non-free
#deb http://security.debian.org wheezy/updates main contrib non-free

然后apt-get update，再执行apt-get dist-upgrade -y后成功升级Debian7。