Create file shares on your IFS using iseries navigator.
Just like windows!

Once you have directories and files share turn on your iSeries Netserver service.
Make sure you configure to start up with server.

Configuring iSeries NetServer properties
To view and configure iSeries NetServer properties, follow these steps:

In iSeries Navigator, expand Network.
Expand Servers.
Click TCP/IP to retrieve a list of the TCP/IP servers available.
Right-click iSeries NetServer and select Properties.
Click Help if you need more information to complete the fields.
When you have completed the fields, click OK.

It’s slick and if you keep your ID’s and passwords in sync with your windows A.D. environment then you can utilize the feature in client access to pass that info along.
They there’s no additional login’s required when you map to the AS400.