vsftpd, add the following directive to /etc/vsftpd/vsftpd.conf:
			local_enable=NO
sudo privileges, the easiest way is to use a PAM list file as described in Section 2.1.4.2.4, “Disabling Root Using PAM”. The PAM configuration file for vsftpd is /etc/pam.d/vsftpd.
				vsftpd, add the username to /etc/vsftpd/ftpusers