конфигурация набора теневых паролей (shadow password suite configuration)
Ошибки (баги) (Bugs)
Much of the functionality that used to be provided by the shadow
password suite is now handled by PAM. Thus, /etc/login.defs is no
longer used by passwd(1), or less used by login(1), and su(1).
Please refer to the corresponding PAM configuration files
instead.