For Ubuntu Desktop or Ubuntu Server with x86_64 arch。

The way to turn on/off swap, or changing the size of swap, on Ubuntu. Other linux distributions are similar.

Never do 'sudo rm -rf /'

Pre-requisite：You need a server with a public IP address to do this.

Install and configure Homebrew with USTC source and turn off homebrew auto-update.

ssh-keygen可以用来生成ssh的秘钥和公钥。通常可以用来自动登录远程服务器，这样可以省去每次ssh时手动输入密码的麻烦；以及使用SSH协议访问git仓库。