As per some email threads and PMRs, the trick to making SA work is to: -
(a) amend \WebSphere\PortalServer\config\properties\SiteAnalyzerLogService.properties as required
(b) run the task WPSConfig.bat update-properties from a command prompt ( from within the \WebSphere\PortalServer\config directory )
(c) restart your Portal server
This then updates the configuration and, you can then log into the WebSphere Application Server administration console ( https://hostname.domain.com:10039/ibm/console/logon.jsp ) and, under Resources -> Resource environment providers -> WP SiteAnalyzerLogService -> Custom properties, to see the settings applied from SiteAnalyzerLogService.properties.
I chose to trace the login actions, so SA.LOG was not created until I first logged into the Portal.
Please see: -
Configuring WebSphere Portal for site analysis logging