:: What is vsftpd
vsftpd is an FTP server for Unix-like systems, including Linux. It is licensed under the GNU General Public License. It supports IPv6 and SSL. – wikipeda
 
:: How to jail / chroot users on vsftpd
+ setup vsftpd.conf

vi /etc/vsftpd/vsftpd.conf
## add this line:
chroot_local_user=YES

+ restarting vsftpd

/etc/init.d/vsftpd restart