最近装了ubuntu18.04 LTS，下载软件有点慢，网上搜了下解决方案，大致是两种：一、把/etc/apt/sources.list文件里的源更换一下，改成阿里云或者其它的镜像的文件；二、更换software&updates里的select best server。

一、更换/etc/apt/sources.list文件里的源

1. 备份源列表

Ubuntu配置的默认源并不是国内的服务器，下载更新软件都比较慢。首先备份源列表文件sources.list：

# 首先备份源列表
sudo cp /etc/apt/sources.list /etc/apt/sources.list_backup

2. 打开sources.list文件修改

选择合适的源，替换原文件的内容，保存编辑好的文件, 以阿里云更新服务器为例（可以分别测试阿里云、清华、中科大、163源的速度，选择最快的）：

# 打开sources.list文件
sudo gedit /etc/apt/sources.list

编辑/etc/apt/sources.list文件, 在文件最前面添加阿里云镜像源：

#  阿里源
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb 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 main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

3. 刷新列表

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install build-essential

下载速度瞬间就起飞了。

4. 其他源

中科大源：

#  中科大源
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

163源：

# 163源
deb http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse

清华源：

# 清华源
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

更换sources.list速度依然还是很慢就请继续往下看第二种方法。

二、更换software&updates里的select best server

这种方法不需要改什么文件，直接在select best server里自动选择。

1. 首先在Show Applications找Software & Updates：

2. 打开software & updates，download from里选择other：

3. 然后点击select best server按钮,它会找到最快的那个,然后点击choose server,就选好镜像了：

我这里搜到的阿里云的源：

4. 把other software选项中除了阿里云的镜像源的对勾都去掉了,目前没有啥影响：

5. 终端里输入sudo apt-get update，速度瞬间快的飞起。

sudo apt-get update

参考

1. 修改ubuntu 18.04的sources.list源为阿里或清华镜像

2. Ubuntu16.04换国内最快源