轉載https://blog.csdn.net/xcyww/article/details/82420651
之前使用apt install下載軟件速度幾乎不動，下載速度以B/s計量。
使用如下方法，切換源之後速度飛起，親測好用，推薦大家。
命令方式
今天在用虛擬機安裝編譯linux內核所需依賴庫的時候，使用 apt-get 指令進行安裝速度非常之不穩定，而且大多時候都很慢。原因是其默認源在國外，因此速度自然不會很快。於是換成阿里的源，速度明顯快了很多（如果是自身網絡問題那就沒辦法了），以下是換源的步驟。
1.打開終端，首先最好備份一下原來的source文件：sudo cp sources.list sources.list.bak 。
2.然後打開source文件，sudo gedit /etc/apt/source.list，將內容替換爲：
#deb cdrom:[Ubuntu 16.04 LTS Xenial Xerus - Release amd64 (20160420.1)]/ xenial main restricted
deb-src http://archive.ubuntu.com/ubuntu xenial main restricted
#Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial main restricted multiverse universe
#Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted multiverse universe
#Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb http://mirrors.aliyun.com/ubuntu/ xenial multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse
#Added by software-properties
deb http://archive.canonical.com/ubuntu xenial partner
deb-src http://archive.canonical.com/ubuntu xenial partner
deb http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted multiverse universe
#Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-security multiverse
3.執行更新：sudo apt-get update
好了，現在可以愉快的下載想要的軟件了。