This chapter describes anonymous tracing, tracing that is not associated with any DTrace consumer. Anonymous tracing is used in situations when no DTrace consumer processes can run. The most common use of anonymous tracing is to permit device driver developers to debug and trace activity that occurs during system boot. Any tracing that you can perform interactively can also be done anonymously. However, only the super user may create an anonymous enabling, and only one anonymous enabling can exist at any time.