Ontap is a very very customized version of FreeBSD, you can't install agent on it. and there no product in the market that requires that.
FAS8080 can run two Modes of Data ONTAP Operation System,, 7-Mode, and Clustered. while Clustered is latest and what most new 8080 shipped with therefor i link only to cluster mode doc. but it's important that in your forward searching about that topic you know what exact Netapp product you are using. as some vendors might only support the legacy 7-mode and not yet adopted to the recent.
in Clustered Data ontap there two methods that software can monitor the access to files on the NetApp:
1. Fpolicy. you can see list of supported solutions that using that method - your product is not there:
2. EVTX And XML standard auditing files: that i suspect that product might know how to use but coulden't find a good public evidence for,
Its also important to know that there an Product level audit log that saves all the operations that the storage admin do. this also might be good to monitor. and can be done most easily with syslog