Some Zend Server components (e.g., Code Tracing) utilize the disk space on your machine. To help you limit the usage of your disk space by these components, Zend Server includes built-in control mechanisms that help you limit the amount of space used.
These mechanisms are defined by component directives (e.g., zend_codetracing.max_disk_space) which limit the total physical space according to your preferences, and periodically (once an hour) clean oldest data that exceeds the specified limits.
For more information on controlling resource usage, see Controlling Resource Usage.