If you are running a WiKID server with a few thousand users or if you want to keep your logs on debug for some reason, then archiving your logs is a good idea. And automation is always a good idea. Here's how to do it:
Download the LogExporter.jar.
On the command line run 'java -jar LogExporter.jar 2 hours' to archive all but the last two hours of logging. The usage is <value> <period> where period can be one of minutes|hours|days|weeks|months|years.
Set up a chron job to do this as frequently as you like.