I tried using the default portal install. I am trying to use CMS Manager (CMS Admin portlet) to upload files and display them using CMS User portlet. I didn't see the directories/files created on the local filesystem. I am looking for guide on how CMS Admin portlet works. Any help on that will be much appreciated.
By default this is stored in Database not on the file system.
You should ask the JBoss Portal questions in the JBoss Portal user forum.