You use many passwords with your servers the administrative password, the private key password and database passwords. Your administrative password is the most important passwords since anyone with that password can configure the servers on your computer. Your private key password is also important. If someone obtains your private key and your private key password, they can create a unauthorized server that appears to be yours, or intercept and change communications to and from your server.
A good password is one you can remember but others cannot guess. For example, you could remember MCi12!mo as “My Child is 12 months old!” A bad password is your child’s name or birthdate.
It is not necessary to incorporate all of the following rules in one password the more rules you use, the better your chances are of making your password more secure:
Passwords should be 6-14 characters long. (Mac passwords cannot be longer than 8 characters)
Avoid using the “illegal” characters: *, ", or spaces
Avoid using words from dictionary (in any language)
Do not make common letter substitutions, like replacing E with 3, or L with 1
Include characters from as many of these classes as possible: