ubantu基本问题解决办法

1、 Could not connect to security.ubuntu.com:80 (91.189.91.93), connection timed out
Reading package lists… Done
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/bionic-security/InRelease Could not connect to security.ubuntu.com:80 (91.189.91.93), connection timed out
W: Some index files failed to download. They have been ignored, or old ones used instead.

sudo apt-get update && apt-get upgrade
2、Ubuntu 扩大虚拟机系统磁盘空间

https://www.cnblogs.com/chenyongjun/p/4604222.html