[Debian] Debian Linux 更换阿里源

刚安装好的Debian系统的默认源一般是国外链接，资源获取效率很低，可以指定为国内源，比如阿里的，步骤如下：

步骤 1.备份系统默认源
cp /etc/apt/sources.list /etc/apt/sources.list.bak

步骤 2. 清空/etc/apt/sources.list
echo "" > /etc/apt/sources.list

步骤 3. 将以下内容添加到/etc/apt/sources.list
deb https://mirrors.aliyun.com/debian stable main contrib non-free
deb https://mirrors.aliyun.com/debian stable-updates main contrib non-free

步骤 4. 更新源列表
apt-get update