On this page you set the file name, file store location, size and number of rotations for the logging target.
Ideally, you want to think about putting the log file within logstore:/// on your raid, if you have it. This way you don't have to worry about filling up your temporary space.
The number of rotations and file size need to be tuned based upon logging level and the volume of logs generated for the selected objects. By default, the selected objects and their references are subscribed, so if the selected objects are a large number of complete services like Multi-Protocol Gateways or Web Service Proxies, then you should expect a large volume of logs.