Centos实战 / su: cannot open session: Permission denied

centos su - 用户名 su: cannot open session: Permission denied

-bash-4.2$ su - lwk
Password: 
Last failed login: Thu Jun 28 15:39:52 CST 2018 from 36.24.223.44 on ssh:notty
There was 1 failed login attempt since the last successful login.
su: cannot open session: Permission denied
-bash-4.2$      

lwk soft nofile 65535
lwk hard nofile 65535