在ubuntu中，默认使用 ubuntu 的官方源http://archive.ubuntu.com/，但是这个官方源在国内下载的速度太慢，甚至只有几十k。于是考虑更换apt源加快下载速度
国内可用镜像源站点很多，可以参考之前的文章国内镜像站推荐，这里以阿里镜像源作ubuntu的apt源
更换镜像源步骤
在 Ubuntu 系统中，可以通过修改/etc/apt/sources.list文件内容来修改 apt 源，通常在镜像站中也给出了更改镜像源的方法，比如阿里镜像站的更换说明：Ubuntu 镜像更换
图形界面配置
新手推荐使用图形界面配置： 系统设置 -> 软件和更新 选择下载服务器 -> “mirrors.aliyun.com”
无图形界面手动更改
- 首先备份
sources.list文件，避免在意外出错情况下能够还原
cd /etc/apt/
sudo cp sources.list sources.list.bak
- 修改
sources.list文件内容
sudo vim sources.list
替换默认的 http://archive.ubuntu.com/ 为 mirrors.aliyun.com
以Ubuntu 14.04.5 LTS为例，最后的效果如下：
deb http://mirrors.aliyun.com/ubuntu/ xenial main
deb-src http://mirrors.aliyun.com/ubuntu/ xenial main
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main
deb http://mirrors.aliyun.com/ubuntu/ xenial universe
deb-src http://mirrors.aliyun.com/ubuntu/ xenial universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-security main
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main
deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security universe
ubuntu 16.04 配置如下
deb http://mirrors.aliyun.com/ubuntu/ xenial main
deb-src http://mirrors.aliyun.com/ubuntu/ xenial main
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main
deb http://mirrors.aliyun.com/ubuntu/ xenial universe
deb-src http://mirrors.aliyun.com/ubuntu/ xenial universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-security main
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main
deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security universe
ubuntu 18.04(bionic) 配置如下
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
- 更新 apt 本地索引
sudo apt update
这个速度变化很明显了，甚至达到了2M多每秒
事实上，对于其他 Linux 发行版更改镜像源，方法也是大同小异的（如 Redhat 系的 yum）
参考：
https://developer.aliyun.com/mirror/ubuntu?spm=a2c6h.13651102.0.0.53322f70NQyRxh