Quoting from the link above:
Deploying Logging
You can enable logging on the Security Management Server (enabled by default), or deploy a dedicated Log Server.
After you deploy the Log Server, you must configure the Security Gateways for logging.
You must execute the function on the remote Log Server when you:
-
Enable or disable a logging related blade or function, including Log Indexing in a server object.
-
Add a new Log Server to the system.
-
Change a Security Gateway's Log Server.
-
Change a Log Server's log settings or make any other Log Server object change.
-
Change anything in the Global Properties that might affect the Log Server.