If you have set the Log On rights for the Storage Manager Agent already to a domain account, you probably haven't selected any CIFS shares for scanning or haven't turned on the File Analysis module on the agent selected for scanning. See the blog below that covers all the steps involved
File Analysis on NAS (NetApp, Celerra, etc.) and Virtual Machines
The agent(s) used to perform file scans can be independent of the agents effectively used as data collectors for performance & capacity polling.