pam

cat /etc/pam.d/login
#%PAM-1.0
auth required pam_securetty.so
auth include common-auth
auth required pam_nologin.so
account include common-account
password include common-password
session include common-session
session required pam_lastlog.so nowtmp
session required pam_resmgr.so
session optional pam_mail.so standard

/etc/securetty
修改
#tty2 加上# -------->root 無法從tty2登入