I have no personal experience of this feature at my site, but there is a 'SCAN/Initialization PHASE', that says Enabling FSA is expected to have a performance impact during the initialization phase only. So, I am guessing depending upon how dense the volume/directories/files are on a given volume, the time factor for initial scan will vary, plus the existing load of the filer at the time of enabling this feature. I am guessing once scan is over, it should show the result.
https://www.netapp.com/media/20707-tr-4867.pdf - Page-5 (Architecture-The runtime of the scanner is proportional to number of inodes, ONTAP filesystem Init Scanner runs in parallel on multiple directories.)
Following command can tell the scan progress percentile.
Cluster01::*> volume analytics show
https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Software/ONTAP_OS/High_or_fluctuating_latency_after_turning_on_NetApp_ONTAP_File_System_...
Related podcast:
https://soundcloud.com/techontap_podcast/episode-270-netapp-ontap-file-systems-analytics
