If you are running web applications or hosting websites on IIS, and have your IIS logging enabled. You are in risk of running out of disk space. Of course the logging is needed for debugging and such. If it is not in use, cleared periodically I think you should just disable it.
Here is how to disable IIS logging:
Open IIS Manager, and select the server in the left hand pane.
Select the logging icon, and click Stop in the right hand pane.
If the logging icon can not be found. It is because the logging function is not installed. And if it is not needed, just keep it that way. You will find it in Role Service, under IIS.
Happy logging!