Vsftp using MySQL for virtual user access

Vsftp uses MySQL to implement virtual user access-Linux Enterprise Application-Linux server application information. For details, see the following. Hello everyone, I recently encountered a problem (with the same title), as shown below: In a book titled linux server configuration full record, I configured vsftp to create a MYSQL table to store the user name and password, to implement virtual user access through MySQL, the following code is used when creating a local ing user
Useradd-d/var/ftp/vuserdir
-S/sbin/nologin vuser
Chmod o + rw/var/ftp/vuserdir
The prompt is the vuserdir folder. After you manually create the folder and continue the above command, the prompt is that the vuserdir folder already exists. Please help us to discuss and solve the problem. Thank you very much, I hope everyone can help me with linux growth path [local] 1 [/local... Thank you.