Retention policies require you to keep Syslog messages in the database for 9 days before...

 By default, Orion NPM retains Syslog messages in the database for seven days before discarding them. This means that any Syslog messages older than seven days are deleted from the database and cannot be viewed or searched in the web console. To change the default Syslog retention period, you need to modify the Database Settings on the Orion Polling Settings page in the web console. You can also use the Database Manager tool to manually delete or archive Syslog messages from the database. References: SolarWinds SCP Study Aid - NPM, page 19; NPM Administrator Guide, page 111.