Enter a password for the primary administrative user name when you are prompted.
出现提示时,输入主管理用户名的密码。
2
The primary instance can run ssh and scp as root with password-less authentication to other instances and vice-versa
对其他实例进行密码身份验证后,主要实例可以以 root 运行ssh 和 scp ,反之亦然
3
If you don't, you need to have some way of uniquely identifying each user in a database table (a primary key, usually an integer), a username (also unique), an E-mail address, a password, etc.