1. 备份原有文件
cp /etc/apt/sources.list /etc/apt/sources.list_bak
2. 编辑sources.list文件
vi /etc/apt/sources.list
#阿里源 deb http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse #deb http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse #deb-src http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
3. 检查是否可以访问外网(ping www.baidu.com)
root@qy-virtual-machine:/opt/application/tsingyun-iot-platform# ping www.baidu.com PING www.a.shifen.com (14.215.177.38) 56(84) bytes of data. 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=1 ttl=55 time=34.9 ms 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=2 ttl=55 time=34.1 ms 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=3 ttl=55 time=34.9 ms 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=4 ttl=55 time=35.2 ms
4. 更新源 (apt-get update)
