ubuntu20.04 换源

1、备份源文件

cp /etc/apt/sources.list /etc/apt/sources.list_bak

2、清空源文件

echo "" > /etc/apt/sources.list

3、换源

编辑文件

vi /etc/apt/sources.list

将下面阿里云的源 复制到文件中

# 阿里云源文件

deb http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse

4、更新缓存

#先清理缓存

sudo apt-get autoclean

#更新缓存

apt update

#软件包升级到最新版本

apt upgrade